Better handling of loading the configuration file. Two things:
* `dirname(__file__)` is empty when the mbslave-sync.py is run from the same dir as the config file
* directory separator ('/') is different across platforms. I use os.path.join() instead.
Merged in tsagias/mbslave/tsagias/better-handling-of-loading-the-configura-1393928190377 (pull request #5)

Better handling of loading the configuration file. Two things:
Schema change release 20
Missing file