Various fixes

This merge request contains fixes for skype-for-business (1b86aa3c), fixes specific to tcp transport tested with sfb (a64612b3, 02f2372c), generic connection check related fixes (f15c5f8d, 4ac8d4d3, 9b895505, 383a819d), adds some more debug (cbd4773a, 48488ed3, 1265322c, b30c68e9), fixes asan heap-use-after-free and memory leaks (02f2372c, 15e578a0, c59deb4c, fda90c66, 527bc5a1, 05b5a022, 09eead59), minor compiler warnings (f1f20836). Commit 9a9bac17 adds a ref on the agent until it completes its async removal of turn refreshes. This patch partially resolves issue #84 (closed), in addition to a modification to farstream that is now expected to wait until agent dispose to destroy its thread loop.