Remove websocket address hack, close #87

Also make AutoNetServer less chatty.
Minimum _required_ version is only 3.0

While we do want the build server to be using the latest version of CMake, there is nothing specifically requiring that we mandate users make use of version 3.1 as well.  Thus, roll 3.0 is the minimum required, while 3.1 is merely the preference.
Merge pull request #303 from leapmotion/ref-warnings

Remove mac warnings
Merge pull request #304 from leapmotion/fix-cmakemin

Minimum _required_ version is only 3.0
Eliminate the use of throw_rethrowable and exception_ptr everywhere

This concept doesn't work that well and isn't necessary anyway
Fix libstdc build

A few missing headers have been reintroduced