Released v2.0.0

Most important changes:
- Added support for POSIX real-time signals - the library itself is now using SIGRTMIN for thread crash detection and for CXC_THROW_MAIN()
- Change: removed support for FINALLY section: it was useless in practice.
- Lots of other small changes and fixes.
- Manpage updated.

Full list of changes in the change logs.

Tests performed on x86, amd64 and armhf (BCM2835) - all passed.