Merge branch 'master' of github.com.

Conflicts:
	libs/core/Jamfile
	libs/core/inc/audiopia/resource.hpp
	libs/core/inc/audiopia/static_collection.hpp
	libs/core/src/static_collection.cpp
	libs/spotify/Jamfile
	utils/audiopia.cpp
Add support for XMPP in audiopia cli executable.