Extract riak_core_connection and tests.

Conflicts:
	ebin/riak_core.app
	src/riak_core_connection.erl
	test/riak_core_connection_mgr_tests.erl
	test/riak_core_connection_tests.erl
	test/riak_core_service_mgr_tests.erl
Remove connection manager and service manager.

Conflicts:
	ebin/riak_core.app
	src/riak_core_connection_mgr.erl
	src/riak_core_service_mgr.erl
Remove ranch dependency.