Use config dir for non-temporary writable files

This is also a (partial) fix for issue jasperproject/jasper-client#119
Add jasperpath import to stt.py
Remove chdir from jasper.py

We're now using absolute paths and don't need it anymore
Merge pull request #203 from Holzhaus/good-riddance-dear-writable-app-dir

Use config dir for non-temporary writable files