added parallax backgrounds for city + sewer
fixed serious problem in city map
updated songs to CC traxxx
added credits screen state
screen manager covers credits
end level flag animated
flag keys and doors use new symbols
end credits added to game
finishing last level shows credits
level shows a "complete" text when finished
tuned the lab

tutorial level
minimalized sewer to just blocks
some blocking for sewer level

needs more work
lava dumpers can have an interval if they need
Merge branch 'master' into dan-dev

Conflicts:
	MagnetBoy/MagnetBoy/MagnetBoyContent/flagDoorAnims.xml
	MagnetBoy/MagnetBoy/MagnetBoyContent/flagDoorSheet.png
	MagnetBoy/MagnetBoy/MagnetBoyContent/flagKeyAnims.xml