Log Message:
Update to 0.1.13. Add Makefile.common to share with gst-plugins1-libnice.

libnice 0.1.13 (2015-04-28)
===========================
Fix build on non-Windows platforms that don't have getifaddrs()
Fix build regression on Windows

libnice 0.1.12 (2015-04-22)
===========================
Fix regression in SDP parser
Make examples work on Windows
Bug fixes on nicesrc

libnice 0.1.11 (2015-04-20)
===========================
API: nice_agent_set_local_credentials() for WebRTC
Nicesink: support GstBufferList
Better warnings on programming errors
Build fixes for Solaris and Windows
Bug and documentation fixes