remove Molpy.sand

replace all calls to Molpy.sand
add some local variables for performance
rename a couple variables for code clarity
remove Molpy.castles

replace Molpy.castles with Molpy.Boosts['Castles'].power
add local variables in several places to avoid multiple lookups
Merge branch 'replace_molpy.vars1' into big_merge_fixes

Conflicts:
	boosts.js
	castle.js
	persist.js