fixes #901 shorter option get/set functions for all types

- Renamed internal nng_*_getx/setx methods with "nni" prefix
- Moved stream get/set option definition macros to options.h and added "NNI_" prefix
- "_PTR" variant of get/set option definition macros is for when first arg is passed as pointer (`nng_stream *s` vs `nng_pipe s`)
- New get/set option functions for `nng_socket` are `nng_socket_get_X` eschewing the previous `nng_getopt` pattern
- Macro-fy legacy getopt/setopt and implement in terms of "new" API
- nng_setopt* use "new" shorter API.  Add missing uint64 set functions.
- Shorter get/set option functions get own man page and old getopt/setopt link to them
- Built with -DNNG_ENABLE_DOC=ON and part of central libnng index
- Update copyright

1 files changed, 144 insertions, 0 deletions

diff --git a/docs/man/nng_socket_get.3.adoc b/docs/man/nng_socket_get.3.adoc
new file mode 100644
index 00000000..d077207d
--- /dev/null
+++ b/docs/man/nng_socket_get.3.adoc
@@ -0,0 +1,144 @@
+= nng_socket_get(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_socket_get - get socket option
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_socket_get(nng_socket s, const char *opt, void *val, size_t *valszp);
+
+int nng_socket_get_bool(nng_socket s, const char *opt, bool *bvalp);
+
+int nng_socket_get_int(nng_socket s, const char *opt, int *ivalp);
+
+int nng_socket_get_size(nng_socket s, const char *opt, size_t *zp);
+
+int nng_socket_get_uint64(nng_socket s, const char *opt, uint64_t *u64p);
+
+int nng_socket_get_string(nng_socket s, const char *opt, char **strp);
+
+int nng_socket_get_ptr(nng_socket s, const char *opt, void **ptr);
+
+int nng_socket_get_ms(nng_socket s, const char *opt, nng_duration *durp);
+
+int nng_socket_get_addr(nng_socket s, const char *opt, nng_sockaddr *addrp);
+
+----
+
+== DESCRIPTION
+
+(((options, socket)))
+The `nng_socket_get()` functions are used to retrieve option values for
+the <<nng_socket.5#,socket>> _s_.
+The actual options that may be retrieved in this way vary.
+A number of them are documented in <<nng_options.5#,nng_options(5)>>.
+
+Additionally transport-specific options and protocol-specific options are
+documented with the transports and protocols themselves.
+
+=== Forms
+
+In all of these forms, the option _opt_ is retrieved from the socket _s_.
+The forms vary based on the type of the option they take.
+
+The details of the type, size, and semantics of the option will depend
+on the actual option, and will be documented with the option itself.
+
+`nng_socket_get()`::
+This function is untyped and can be used to retrieve the value of any option.
+The caller must store a pointer to a buffer to receive the value in _val_,
+and the size of the buffer shall be stored at the location referenced by
+_valszp_.
++
+When the function returns, the actual size of the data copied (or that
+would have been copied if sufficient space were present) is stored at
+the location referenced by _valszp_.
+If the caller's buffer is not large enough to hold the entire object,
+then the copy is truncated.
+Therefore the caller should check for truncation by verifying that the
+returned size in _valszp_ does not exceed the original buffer size.
++
+It is acceptable to pass `NULL` for _val_ if the value in _valszp_ is zero.
+This can be used to determine the size of the buffer needed to receive
+the object.
++
+TIP: It may be easier to use one of the typed forms of this function.
+
+`nng_socket_get_bool()`::
+This function is for options which take a Boolean (`bool`).
+The value will be stored at _bvalp_.
+
+`nng_socket_get_int()`::
+This function is for options which take an integer (`int`).
+The value will be stored at _ivalp_.
+
+`nng_socket_get_ms()`::
+This function is used to retrieve time <<nng_duration.5#,durations>>
+(such as timeouts), stored in _durp_ as a number of milliseconds.
+(The special value ((`NNG_DUR_INFINITE`)) means an infinite amount of time, and
+the special value ((`NNG_DUR_DEFAULT`)) means a context-specific default.)
+
+`nng_socket_get_ptr()`::
+This function is used to retrieve a pointer, _ptr_, to structured data.
+The data referenced by _ptr_ is generally managed using other functions.
+Note that this form is somewhat special in that the object is generally
+not copied, but instead the *pointer* to the object is copied.
+
+`nng_socket_get_size()`::
+This function is used to retrieve a size into the pointer _zp_,
+typically for buffer sizes, message maximum sizes, and similar options.
+
+`nng_socket_get_string()`::
+This function is used to retrieve a string into _strp_.
+This string is created from the source using `<<nng_strdup.3#,nng_strdup()>>`
+and consequently must be freed by the caller using
+`<<nng_strfree.3#,nng_strfree()>>` when it is no longer needed.
+
+`nng_socket_get_uint64()`::
+This function is used to retrieve a 64-bit unsigned value into the value
+referenced by _u64p_.
+This is typically used for options related to identifiers, network
+numbers, and similar.
+
+== RETURN VALUES
+
+These functions return 0 on success, and non-zero otherwise.
+
+== ERRORS
+
+[horizontal]
+`NNG_EBADTYPE`:: Incorrect type for option.
+`NNG_ECLOSED`:: Parameter _s_ does not refer to an open socket.
+`NNG_EINVAL`:: Size of destination _val_ too small for object.
+`NNG_ENOMEM`:: Insufficient memory exists.
+`NNG_ENOTSUP`:: The option _opt_ is not supported.
+`NNG_EWRITEONLY`:: The option _opt_ is write-only.
+
+== SEE ALSO
+
+[.text-left]
+<<nng_dialer_get.3#,nng_dialer_get(3)>>,
+<<nng_listener_get.3#,nng_listener_get(3)>>,
+<<nng_pipe_get.3#,nng_pipe_get(3)>>,
+<<nng_socket_set.3#,nng_socket_set(3)>>,
+<<nng_strdup.3#,nng_strdup(3)>>,
+<<nng_strerror.3#,nng_strerror(3)>>,
+<<nng_strfree.3#,nng_strfree(3)>>,
+<<nng_duration.5#,nng_duration(5)>>,
+<<nng_options.5#,nng_options(5)>>,
+<<nng_socket.5#,nng_socket(5)>>,
+<<nng.7#,nng(7)>>