Use struct keyword consistently with sockaddr and sockaddr_in

Small code simplification

Fix the message decoder to ignore reserved flags.

Failing to clear the reserved flags, the decoder may produce
messages with 'identity' and 'shared' flags set.
This unintended modification of message flags can lead to memory
errors or asserion failures.

Fixes issue #309

Use the hiccup mechanism to notify the socket end of the pair of the change in state, and have it shutdown that end, and shutdown the local end normally. This seems to resolve the shutdown and race condition issues.

Consolidate TCP-specific common code into their own files.

The TCP keepalive tuning code has been moved into the newly added
files; this also allows future TCP-specific code to be added into
these files, without bloating the IP level code and establishes a
known file structure for other IP-based transports.

Remember: this is a no-op change, hence no API or functionality
was changed as part of this commit.

Change connection failure test to use an invalid hostname

- invalid hostname set to 0mq.is.the.best (naturally!)
- issue happens as other valid-like non-existent hostnames were
  redirected by buggy Cable/ISP DNS servers

Reverted to a simpler shutdown. This seems to disconnect and reconnect the pipe properly, but there is a problem in overall shutdown when the pipe has blocked and reconnected - the session seems to get terminated() called on it only in shutdown for the original pipe, by which point it has been replaced. I am not sure at the moment why this only happens then, but this does mean this patch is broken at the moment

Remove unused variable which causes build to fail with -Werror

Check if SO_NOSIGPIPE is defined

Bumped version for next release (3.3.0)

The previous code to block the socket from receiving on that pipe during a disconnect was vulnerable to a race condition. This code calls with the terminate functions of both ends of the pipe - I believe this should be safer. This required storing a pointer to the socket end of the pipe

When detaching a pipe, as well as checking the delay on connect sockopt is set, also ensure that the protocol is not pgm or epgm as we are not implementing the functionality for multicase types

Fix build on HPUX 11iv3

Fix up build on AIX7

Fix build on RHEL5 and SLES10

The socket length variable for getsockname and accept must be an
(int *) instead of a (socklen_t *) on HPUX.
Signed-off-by: AJ Lewis <aj.lewis@quantum.com>

GCC 4.1.2 on RHEL5 and SLES10 don't like not having a newline at the
end of a source file, and error out if it's missing.
Signed-off-by: AJ Lewis <aj.lewis@quantum.com>

Copy logic from zmq.cpp into device.cpp for getting poll.h included.

Ensure that zmq.h is included *after* poll.h in both zmq.cpp and
device.cpp.
Signed-off-by: AJ Lewis <aj.lewis@quantum.com>

Removing unnecessary outpipe values that had been used for reconnecting existing pipes - no longer needed when using a pipe term for the delay_attach situation.

Remove unnecessary extra test in pipe assertion - now we are terminating pipes we don't need to allow the case in which a pipe is rebound to the same sink

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.

Rebinding on reconnection to allow for the pipe blocking will set the event sink again, which will cause an assert to be triggered. I have modified that to allow for setting the same sink to be OK. I believe this should be ok - on termination, if a pipe hasn't reconnected, it would just attempt to be erased from the pipes list again, which is reasonable

Fix condition so that PGM and EPGM sockets always create pipes immediately, even if delay_attach_on_connect is set. This allows passing through the icanhasall flag, and is realistic given the fact those protocols should be able to connect immediately

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.