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
fixed a bug in MetaK.isUnifiable; added comments
some refactoring to clean up KItem
fixed failing test by using regex to match result
refactoring: extract the computation of sort from KItem constructor to helper method
inlined all constants in KSorts and removed the class
attempt to remove dependency on collections15
fixed regex pattern
didn't properly extract the helper method
added .recommenders for Eclipse to gitignore
added collections15 library back to .classpath file
Merge branch 'unified-builtins2' into singleton-pattern-for-sorts-in-Java-backend
fixed whitespace
Merge branch 'unified-builtins2' into singleton-pattern-for-sorts-in-Java-backend

Conflicts:
	src/javasources/KTool/src/org/kframework/backend/java/kil/KItem.java
	src/javasources/KTool/src/org/kframework/backend/java/symbolic/UseSMT.java
Merge pull request #715 from yilongli/singleton-pattern-for-sorts-in-Java-backend

Flyweight pattern for sorts in java backend