Session API fixes

There's a flaw in how the session's lifetime was connected
to the lifetime of the connect/close future. It was possible for
the session thread to join itself when it freed a future object
becuase it had the final reference.
Fix for connect hang when LB policy determines a host is ignored
Removing TESTING_DIRECTIVE option/define and code associated with the session guard test
Adding a test for the connect hang when LB policy determines a host is ignored
Removing connection notification from special testing case (backpressure)
Added logging example and docs.

- Update all the example to use the "Unlicense".
Update README.md
Fixed async/close integration test
Fixed formatting
Updating tests to work with logger changes and timing issues
Updated logging example and docs
Wrong README
Example cleanup

memory leaks and segfaults
Typo in test_pool connection error message.
Merge remote-tracking branch 'origin/CPP-190' into rc1

Conflicts:
	test/integration_tests/src/test_pool.cpp