compatibility: Make code compile and run with ZeroMQ version 3.2 and newer.
PollingZMQSocket,poll: Use const reference for 'ZMQException'.
PollingZMQSocket,run: Emit signal in case of a poll error.
repo: Add '.gitignore' file.
changelog: Update.
changelog: Update.
license: Updated copyright year.
readme: Fixed typo.
readme: Added 'Dependencies' section.
extrnals,cppzmq: Added 'cppzmq' as submodule.
setup-project: Set executable bit of shell script.
merge: Merged with 'master'.
readme: Fixed section 'Dependecies'.