* [docu]: update AUTHORS

Contributors can be found by calling:
git shortlog -s -n

Special Thanks: section is given to
Marti - for his helpful hints about CM.
Graeme - many ideas and the CMM context and renderer split
Gerhard - initial shader code
Jan-Peter - for grouping idea (policy) and some options
Tomas - for work on the XCM stuff, which is now in libXcm
Kåre - for intensive discussing device abstraction
Hal, Boudewijn - for overall support