partial commit
Merge branch 'master' into leveled
Latest updates from master to leveled
leveled lookup works with K levels only, where K is the lenght of langest terminal chain. Does not work for ambiguous grammars yet.
Leveled loopup works for ambigous grammars.
validity arrays removed.
Bug in storing SPPF nodes in levels fixed.
Only N levels of descriptor sets is created at each time.
fixing the indexFor method for open addressing hashset and map.