prosody: import from packages, add myself as the maintainer

This adds the prosody package from the old svn tree. Ive updated
the licensing information and will maintain the package in the
future. This request also updates prosdoy to the latest version 0.9.4.

Signed-off-by: Thomas Heil <heil@terminal-consulting.de>
Merge pull request #53 from heil/prosody

prosody: import from packages, add myself as the maintainer