Merge pull request #72 from ianbarber/master

Fix some doc rendering bugs
Update zmq.c

Sometimes the "zval_ptr_dtor" in "recvMulti" make a segfault, but the FREE_ZVAL works. This might not be 

My System:
I am using PHP 5.4.6-1ubuntu1.1 with zmq (latest master) as _only_ Extension with libzmq 3.2.2.

# php -i | grep zmq
zmq
libzmq version => 3.2.2
Merge pull request #76 from h4cc/patch-1

Update zmq.c
Resolved mkoppanen/php-zmq issue 83

Added ZMQ::SOCKOPT_TCP_KEEPALIVE constant and ZMQ::getSockOpt and ZMQ::setSockOpt code.
Reverted version number change
Merge pull request #84 from alethia7/enable_keepalive

Resolved mkoppanen/php-zmq issue 83
Update version
Fixing copy and paste typo in documentation

Also tweaked alias reference to current standard.