crtmpserver: import from packages, add myself as the maintainer

This adds the crtmpserver package from the old svn package tree. I adopt
the licensing information and will maintain the package in the future. I
also updated the package to the latest version and ensure that is
building on x86_64, ar71xx and avr32.

Signed-off-by: Thomas Heil <heil@terminal-consulting.de>