fixes #143 Protocols and transports should be "configurable"

This makes all the protocols and transports optional.  All
of them except ZeroTier are enabled by default, but you can
now disable them (remove from the build) with cmake options.

The test suite is modified so that tests still run as much
as they can, but skip over things caused by missing functionality
from the library (due to configuration).

Further, the constant definitions and prototypes for functions
that are specific to transports or protocols are moved into
appropriate headers, which should be included directly by
applications wishing to use these.

We have also added and improved documentation -- all of the
transports are documented, and several more man pages for
protocols have been added.  (Req/Rep and Surveyor are still
missing.)

1 files changed, 20 insertions, 15 deletions

diff --git a/src/core/protocol.h b/src/core/protocol.h
index 5db259f0..39bde059 100644
--- a/src/core/protocol.h
+++ b/src/core/protocol.h
@@ -147,21 +147,26 @@ extern int nni_proto_open(nng_socket *, const nni_proto *);
 // Protocol numbers are never more than 16 bits.  Also, there will never be
 // a valid protocol numbered 0 (NNG_PROTO_NONE).
 #define NNI_PROTO(major, minor) (((major) *16) + (minor))
-enum nng_proto_enum {
-	NNI_PROTO_NONE          = NNI_PROTO(0, 0),
-	NNI_PROTO_PAIR_V0       = NNI_PROTO(1, 0),
-	NNI_PROTO_PAIR_V1       = NNI_PROTO(1, 1),
-	NNI_PROTO_PUB_V0        = NNI_PROTO(2, 0),
-	NNI_PROTO_SUB_V0        = NNI_PROTO(2, 1),
-	NNI_PROTO_REQ_V0        = NNI_PROTO(3, 0),
-	NNI_PROTO_REP_V0        = NNI_PROTO(3, 1),
-	NNI_PROTO_PUSH_V0       = NNI_PROTO(5, 0),
-	NNI_PROTO_PULL_V0       = NNI_PROTO(5, 1),
-	NNI_PROTO_SURVEYOR_V0   = NNI_PROTO(6, 2),
-	NNI_PROTO_RESPONDENT_V0 = NNI_PROTO(6, 3),
-	NNI_PROTO_BUS_V0        = NNI_PROTO(7, 0),
-	NNI_PROTO_STAR_V0       = NNI_PROTO(100, 0),
-};
+
+// Protocol major numbers.  This is here for documentation only, and
+// to serve as a "registry" for managing new protocol numbers.  Consider
+// updating this table when adding new protocols.
+//
+// Protocol     Maj Min Name       Notes
+// -------------------------------------------
+// NONE          0   0             reserved
+// PAIRv0        1   0  pair
+// PAIRv1        1   1  pair1      nng only, experimental
+// PUBv0         2   0  pub
+// SUBv0         2   1  sub
+// REQv0         3   0  req
+// REPv0         3   1  rep
+// PUSHv0        5   0  push
+// PULLv0        5   1  pull
+// SURVEYORv0    6   2  surveyor   minors 0 & 1 retired
+// RESPONDENTv0  6   3  respondent
+// BUSv0         7   0  bus
+// STARv0      100   0  star       mangos only, experimental
 
 extern int  nni_proto_sys_init(void);
 extern void nni_proto_sys_fini(void);