add a player attribute that defines her view range
run sprite animation even before it is in view range - eliminate seeing doors close the first time they enter our view range
simplified the upgrade namespace
rename mana to power, and clean up the rest of the character stats names
allow applying upgrades, purging them, and some helpers
add install_upgrade()
fix debug command installing upgrades on a level where none are define for that level
spec update upgrades
knocked off some todos