VERSION 1.1.4: Improved path detection, improved anti-recursion code,…

… and Network Containers BETA

ZeroTier One version 1.1.4 has several improvements to path stability and
path learning logic. It also contains the BETA version of Network Containers!

See netcon/README.md and https://www.zerotier.com/product-netcon.shtml for more
information.

Improvements in 1.1.4:

 - Paths are now confirmed more aggressively on inactivity. This version can
   usually detect a dead direct path in under 10 seconds vs 1-2 minutes in
   previous versions.
 - Logic to prevent recursion has been overhauled. The old versions had code
   that explicitly checked packet contents (AntiRecursion.hpp). This is now
   gone in favor of a function that checks IP addresses of ZeroTier devices
   when paths are learned or probed. This is both more efficient and less
   prone to edge case failures. Testing in several complex environments has
   shown that this eliminates a few edge cases where inappropriate paths would
   be used.