0.22.1

Updated Mechanism driver to specify fixed MAC address for Calico tap interfaces.
Prevent the possibility of gevent context-switching during garbage collection in Felix.
Increase the number of file descriptors available to Felix.
Firewall input characters in profiles and tags.
Implement tree-based dispatch chains to improve IPTables performance with many local endpoints.
Neutron mechanism driver patches and docs for OpenStack Kilo release.
Correct IPv6 documentation for Juno and Kilo.