Updated libzmq to match RFCs 

- was not looping to read all input from peer
- broke on OS/X specifically

Clarified zmq_socket.txt ZMQ_STREAM section, added HTTP server example

- tests that system can provide at least 1,000 sockets
- we could expand on this but this covers the main case of OS/X
  having a too-low default limit of 256 handles per process

mark test_linger as expected failure

rather than pretending it passes 

* 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

Fix MSVC 2008 and 2010 project files

Fix cmake file for security tests

Fixed ZAP authentication

- if ZAP server returns anything except 200, connection is closed
- all security tests now pass correctly
- test_security_curve now does proper client key authentication using test key
- test_security_plain now does proper password authentication

Fixed regression tests

- Split off NULL security check from PLAIN
- Cleaned up test_linger code a little
- Got all tests to pass, added TODOs for outstanding issues
- Added ZAP authentication for NULL test case
- NULL mechanism was not passing server identity - fixed
- cleaned up test_security_plain and removed option double-checks (made code ugly)
- lowered timeout on expect_bounce_fail to 150 msec to speed up checks
- removed all sleeps from test_fork and simplified code (it still passes :-)

add test_linger

Adding ability for a context to be terminated in a forked child process

Remove delay options

avoids -Wall failures comparing int to uint

test failed auth for both PLAIN and CURVE

Terminate context in a child process of fork() to replace file descriptors to not interfere with parent process's context

tests that default LINGER (-1) ensures message delivery.

Note: it fails for large messages ( > 1MB, depending on the system).

Change name of icanhasall to subscribe_to_all

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.

adds expect_bounce_fail test function

which is like bounce, but fails if messages arrive.

This test fails because PLAIN authentication doesn't actually reject connections

Disable failing tests on windows.