Preparation for packaging

Man-Page: Added section about the installation location
Makefile: prepare for Debian, cleanup

Documentation enhancements

Documentation was enhanced: added man page.
Two small C programs were added: tcp_client and tcp_server.
Debian specific files / directories were removed.

Stable Release: Rewrite complete

This is the stable release of the re-implementation of the libkeepalive functionality.
All test (even with Java) passed.