Fix a bug in trie implementation

When removing keys for a specified value, make sure we drop
empty node table. Failing to do this can lead to asserion failure.

Refs: http://lists.zeromq.org/pipermail/zeromq-dev/2012-June/017589.html

declare struct iovec

avoids warnings of the form:

warning: 'struct iovec' declared inside parameter list
warning: its scope is only this definition or declaration, which is probably not what you want

when building downstream projects

Fix missing ENETRESET for Jira #LIBZMQ-329.

Missing semi-colon makes Windows compilation fail, Missing files in WIndows solution file

Add errno fallback values for MSVC2008.

Reworked ZMQ_FAIL_UNROUTABLE to actually work as it was intended.

Fix open_socket to return -1 (INVALID_SOCKET on Windows) on error

Connecter cleanups

Calling close () when the underlying socket is invalid
triggers an assertion failure.

Make start_connecting () to have singe exit point.

The patch is meant to make the code easier to understand.
The 'wait' attribute is replaced by 'delayed_start'
and 'timer_started' attributes. The former is constant and
is initialized in the constructor. The latter is a flag
reflecting whether a timer has been started and changes during
the lifetime of the object.

current libzmq not compiling with android NDK

- Android crosscompiler shows a warning about two signed/unsigned checks
  on compilation, this patch adds casts to avoid this, so zmq3.x can
  compile on it.

Correct typo: add missing single quote.

Fix #LIBZMQ-329 assertion on WSAEACCES

{tcp|ipc}_listener: close socket when set_address () fails

Add unistd header to test

For sleep and usleep

Add newline to end of new test file

Add ZeroMQ branding.

Add ZMQ_DELAY_ATTACH_ON_CONNECT sockopt

Update bind and connect documentation for clarity

Rename the pipeset to terminating_pipes, as suggested by Martin H. Adds
asserts to test the pipe is contained in the terminating set where
appropriate.

The previous note in connect introduced but did not elaborate on the
requirement to bind before connect in inproc. As that discussion is in
detail in the inproc docs link to there.

Based on discussion with Steve O on the list, make the difference
between bind and connect usage more clear, and add a note reflecting the
fact that inproc must have bind before connect to reinforce the
information in zmq_inproc.