Bug 116 autotype single keycode

Please take a look at this branch which implements our single keycode idea.
- use standard mappings for keysyms which require no modifiers or shift.
- use a dedicated keycode for all other keysyms.

The changes are quite comprehensive but save approximately 200 lines of code and work around the issues with figuring out modifiers other than shift.

I've successfully tested the code on my machine with en, de, de@CH and fr keyboard layouts and everything worked fine.