Began to work on a Maven multi module configuration.

Only created the parent project so far.
Removed unused jars.
Removed ant build script.
Moved simpledance sources into a real subfolder.
Ignore all target directories.
Removed explicitly (and wrongly) specified group id.
Moved swt repo declaration into the parent module.
Removed the name of the module.
Removed the binding of the javadoc generation to the compile phase again.
Added separate sub module for each target platform.