fixed issue introduced by changes in the sort infrastructure; fix issue with wrongly constructed KItems
Merge pull request #703 from yilongli/alpha-k-rewrite-machine

Prototype k rewrite machine
added regression test
forgot copyright
Merge pull request #707 from andreistefanescu/fix

Fix
Deprecate Production.getLabel
Merge pull request #712 from kframework/deprecate_getlabel

Deprecate Production.getLabel
created a class Sort to represent sort
removed AddPredicates pass from java backend
included Apache Commons Collections 4.0
added a defensive assertion and some javadoc
minor
implemented memoization to speed up computing the sort inforamtion of a KItem