Handling TODOs.
- The userspace application no longer starts and ends a connection whenever it
wants to send something to kernelspace.
- Fixed a truckload of config-related bugs.
- Improved the userspace app's error messages.
Merge branch 'master' of github.com:NICMx/NAT64
Finished the merging of filtering and fixed some unit tests.
the bib_session and pool4 tests still need tweaking.