Allow --configfile and --statsfile to take a path (enables portable mode)

[gitterspec]

For example brainworkshop --configfile ./subdir/config.ini or brainworkshop --configfile C:\config.ini

This would allow the app to be completely portable.

[xantares]

usually this is more set via an environement variable like XDG_CONFIG_DIRS

[gitterspec]

usually this is more set via an environement variable like XDG_CONFIG_DIRS
I tried setting this but it does not seem to have any effect in Windows.