[Fix #218] return null when there is no uninstantiated variables left
[Fix #219] fix range iterator of enumerated integer variable
[doc] udpate doc
Merge branch 'develop' of github.com:chocoteam/choco3 into develop
[fix bin table cstr] correct CouplesTable
Merge branch 'develop' of github.com:chocoteam/choco3 into develop

Conflicts:
	CHANGES.md
Merge branch 'develop' of github.com:chocoteam/choco3 into develop
[doc] partial commit
[doc] partial commit (examples java files)
[doc] partial commit
[Issue #191]: disabled fake history by default
Operator: no more space removal in Operateor.get(String name)
Remove vars.clone() from Propagator constructor
Remove DSL based engine
Move queues directory in from solver/propagation/ to util/objects/
[doc] partial commit
merge develop