KDECompilerSettings

[Alex Merry]

A quick warning: since the alpha is looming close, and we want these
changes to have the maximum testing possible, I'm going to commit the
various changes to KDECompilerSettings that I have queued up tomorrow.

This includes the changes currently on reviewboard, as well as a broad
reorganisation of the file.  There are then a few more changes that can
be made (which will be marked with TODOs or FIXMEs in the file), but I'd
like some compile-everything tests first.

Alex