Solution: update for 2015

Fixes #1320

Revert "linking fd to pipe identity via socket option"

This reverts commit fe3e8c5c.

Conflicts:
	include/zmq.h
	src/pipe.hpp
	src/session_base.cpp

- add const modifier to address parameter of event generating functions

Specifically:

* zmq_event_t should not be used internally in libzmq, it was
  meant to be an outward facing structure.

* In 4.x, zmq_event_t does not correspond to monitor events, so
  I removed the structure entirely.

* man page for zmq_socket_monitor is incomplete and the example
  code was particularly nasty.

* test_monitor.cpp needed rewriting, it was not clean.

- renamed to ZMQ_CONNECT_RID
- fixed whitespace malformating around previous patch
- renamamed next_peer_id to next_rid in preparation for
  larger rename of IDENTITY to ROUTING_ID

Note: ZMQ_CONNECT_RID has no test case and no entry in the man
page, as yet.

Fixed compile issue with missing member of socket_base.  Changed ZMQ_NEXT_IDENTITY to ZMQ_NEXT_CONNECT_PEER_ID.

Fixed case where ZMQ_NEXT_CONNECT_PEER_ID is used in ROUTER, and ROUTER does not read the identity message from the connected pipe.

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

icanhasall is cute (for now), but the effect of the variable is clear
only after tracking down its origin reading the commit. This change is
intended to make it easier for people to have some intuition about its
effect from its name.

Looks like linger is honoured properly, but shutting down the session
causes the pipe termination to come from that side - because the local
pipe then shuts down right away it seems to trigger a terminated on the
other end instead of waiting. This way we trigger the termination from
the local end and then terminate the session.

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.

- fixes LIBZMQ-476 and LIBZMQ-475

Copy monitor specific event endpoints to event messages as the engine etc. can be released at anytime

Significantly reworked the monitoring infrastructure with a more granular per socket API and to play well with monitoring endpoints in application threads

There are three versions of monitor_event(), all taking
variadic arguments. The original code just has the first one
creating a va_list and passing that va_list variadically to
the second one... which creates a new va_list and passes it
variadically to the third one... and of course everything
blows up when we try to pull a non-va_list argument off the
stack.

The correct approach matches the C standard library's use
of printf/vprintf, scanf/vscanf, and so on. Once you make
a va_list, you must pass it only to functions which expect
a va_list parameter.

Revert "Fix a number of whitespace issues in various parts of the code, add validation to most calls on the test and take a first stab at implementing the reconnection pipe blocking."

This reverts commit 6f6466f0.

Revert "On the advice of Martin Hurton, removed the new command type and just terminated the pipe in a reconnect situation, and notified the socket of the same. This handles the blocking properly, but at the cost of potentially losing in flight messages. However, this is a reasonable trade off given how much simpler it makes the patch."

This reverts commit c13f1d52.

On the advice of Martin Hurton, removed the new command type and just terminated the pipe in a reconnect situation, and notified the socket of the same. This handles the blocking properly, but at the cost of potentially losing in flight messages. However, this is a reasonable trade off given how much simpler it makes the patch.

Fix a number of whitespace issues in various parts of the code, add validation to most calls on the test and take a first stab at implementing the reconnection pipe blocking.

It didn't seem straightforward to use any of the existing process calls, so I have added a new command to command_t and friends called detach. This instructs the socket_base to remove the pipe from it's pipe list. The session base stores a copy of the outpipe, and will resend the bind command on reconnection. This should allow balancing again.

socket. Thus, it is shared between subsequent calls
to xs_recv (and xs_send). That in turn significantly
limits the number of invocations of  getimeofday (or similar)
when timeouts are used and recv/send is called in a
tight loop.

* Implemented new ctx API (_new, _destroy, _get, _set)
* Removed 'typesafe' macros from zmq.h
* Added support for MAX_SOCKETS (was tied into change for #337)
* Created new man pages

We use a distinct context initialisation function to specify
all sockets derived therefrom will be thread safe.

However the inheritance is done exclusively in the C interface.
This is not really correct, but it is chosen to minimise
interference with the existing C++ code, including any
construct or other calls within the C++ code base.
Semantically the C++ code should be unchanged,
physically some data structures and extra methods are
provided by they're only used from the C binding.