added builtin size operation for collections

Conflicts:
	include/builtins/list.k
	include/builtins/map.k
	include/builtins/set.k
progress on heap patterns
heap patterns work; reverse proved
reverse proved also with the content sequence constraint; some refactorings
refactored list, map and set k files
fixed issue introduced by changes in the sort infrastructure; fix issue with wrongly constructed KItems
some fixes for JS; added all hooks for builtin maps
refactored maps and sets; added the builtin operations for them
merged unified-builtins2
merged unified-builtins2 (part 2)
fixed whitespaces
minor changes to AC collections
removed unused class
fixed minor issue
hack for Term#substituteAndEvaluate
fixed copyright
fixed minor issue with List hook
fixed bug introduced by this merge in CompileDataStructures
fixed wcet to use explicit |-> instead of lookup
added verification test