clarify comment
styles fixes from PyCharm
update bug URL
many more thoughts about long term plans
- implemented While loops
- killed predictor keyword support -> raise an exception instead of a warning
- simplified attaching processes by implementing the method in ProcessGroup
- renamed all_variables func to all_symbols to more accurately reflect what it does
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/data.py
	tests/functional/simulation.yml