We use metadata_t directly. No need for generic interface now.

- copy and move message operations are updated to maintain proper
  reference count of properties object
- zmq_msg_gets updated to use i_properties interface to fetch property
  value
- setter/getter added to msg_t class

The get_credential () member function returns
credential for the last peer we received message for.
The idea is that this function is used to implement user-level API.

Also moved the fd field from message content to message itself

This patch allows client applications to retrieve the remote endpoint from a message that originated from a tcp socket

* Command names changed from null terminated to length-specified
* Command frames use the correct flag (bit 2)
* test_stream acts as test case for command frames
* Some code cleanups

Copyrights had become ads for Sustrik's corporate sponsors, going against the original
agreement to share copyrights with the community (that agreement was: one line stating
iMatix copyright + one reference to AUTHORS file). The proliferation of corporate ads
is also unfair to the many individual authors. I've removed ALL corporate title from
the source files so the copyright statements can now be centralized in AUTHORS and
source files can be properly updated on an annual basis.

When a peer reconnects, the router socket receives an identity
message containing this peer id. When this happens, the current
implementation crashes.

This patch makes a router socket to silently ignore all identity
messages coming from reconnected peers.

* Fixed use of ssize_t in zmq_msg_t class
* Corrected error after merge, old reference to inner_fctname (broke build)

However, the "durable socket" behaviour wasn't re-added.
Identities are used solely for routing in REQ/REP pattern.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Ben Gray <ben@benjamg.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

GENERIC allows to use 0MQ as a dumb networking framework.
It provides user with connect/disconnect notifications.
Also, each inbound message is labeled by ID of the connection
it originated from. Outbound messages should be labeled by
the ID of the connection to send them to.

To distinguish connect/disconnect notifications from common
messages, COMMAND flag was introduced.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Till now the VSM buffer was aligned to 16 bit boundary
which could possibly cause problems on RISC architectures
when accessing the message data in unsafe manner.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

So far there was no distinction between message parts used by 0MQ
and message parts used by user. Now, the message parts used by 0MQ
are marked as 'LABEL'.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

The two functions had different calling conventions (C vs. C++).
It is fixed now.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

This patch addresses serveral issues:
1. It gathers message related functionality scattered over whole
   codebase into a single class.
2. It makes zmq_msg_t an opaque datatype. Internals of the class
   don't pollute zmq.h header file.
3. zmq_msg_t size decreases from 48 to 32 bytes. That saves ~33%
   of memory in scenarios with large amount of small messages.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

C and C++ headers moved from bindings/ to include/, bindings/ removed
--with-c and --with-cpp options to configure removed, C and C++ now built
and installed by default