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