fixes #286 nng_pair0_open (and all others) need man page

fixes #279 consider restructuring man sections

This represents a rather significant rework, and major editing
effort, for the entire set of manual pages.

All of the pages now have a section number in their filename;
this assists in some other tooling, particularly ebook generation
as every link needs to be programmatically modified when combined
into an ebook.

Section 5 is introduced, and populated with pages for the main
types, and all options are now documented.

Numerous errors have been corrected, including rewriting certain
portions such as the header section of the surveyor protocol.

Much work has been done to facilitate index generation, although
certainly more work remains here.

Every internal link within these pages now resolves; there are no
more dead links.  (This is required to generate Kindle format books.)

1 files changed, 57 insertions, 0 deletions

diff --git a/docs/man/nng_aio_result.3.adoc b/docs/man/nng_aio_result.3.adoc
new file mode 100644
index 00000000..38208d77
--- /dev/null
+++ b/docs/man/nng_aio_result.3.adoc
@@ -0,0 +1,57 @@
+= nng_aio_result(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_aio_result - return result of asynchronous operation
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_aio_wait(nng_aio *aio);
+----
+
+== DESCRIPTION
+
+The `nng_aio_result()` returns the result of the operation associated
+with the handle _aio_.
+If the operation was successful, then 0 is returned.
+Otherwise a non-zero error code is returned.
+
+NOTE: The return value from this function is undefined if the operation
+has not completed yet.
+Either call this from the handle's completion
+callback, or after waiting for the operation to complete with
+<<nng_aio_wait.3#,`nng_aio_wait()`>>.
+
+== RETURN VALUES
+
+The result of the operation, either zero on success, or an error 
+number on failure.
+
+== ERRORS
+
+`NNG_ETIMEDOUT`:: The operation timed out.
+`NNG_ECANCELED`:: The operation was canceled.
+
+Various other return values are possible dependending on the operation.
+
+== SEE ALSO
+
+<<nng_aio_abort.3#,nng_aio_abort(3)>>,
+<<nng_aio_alloc.3#,nng_aio_alloc(3)>>,
+<<nng_aio_wait.3#,nng_aio_wait(3)>>,
+<<nng_strerror.3#,nng_strerror(3)>>,
+<<nng_aio.5#,nng_aio(5)>>,
+<<nng.7#,nng(7)>>