Multiple file loading; tmp disabling variabe redef

Now the python modules will be imported using the -f parameter.

I temporarily disable the variable redefinition - I'd have to change it a lot
and I'm probably not going to keep it like this anyway.

Implements: issue #7
Issue #7: Redefine config by task names

Now you can only redefine stuff in the task configurations, not any variable in
the files.
minor bug fix