Code cleanup

[yacoob]

In no particular order:

• merge bits of play.py (like keyboard handling) to other places, to make them work in main blitzloop
• move all code not related to the gameplay to blitzloop-tools (candidates: audiotest.py, record.py, steptool.py, timetool.py)
• pylint all the things
• remove dead code
• add some comments to make blitzloop code more parseable :)

All of those tasks are tedious but will have a positive effect on the codebase.