Merge branch 'generators'

Conflicts:
	src/main/scala/concrete/IntDomain.scala
	src/main/scala/concrete/constraint/semantic/AbsDiffAC.scala
	src/main/scala/concrete/constraint/semantic/AbsDiffBC.scala
	src/main/scala/concrete/constraint/semantic/AbsDiffConst.scala
	src/main/scala/concrete/constraint/semantic/AddAC.scala
	src/main/scala/concrete/constraint/semantic/AddBC.scala
	src/main/scala/concrete/constraint/semantic/Eq.scala
	src/main/scala/concrete/constraint/semantic/MulAC.scala
	src/main/scala/concrete/constraint/semantic/MulBC.scala
	src/main/scala/concrete/constraint/semantic/Square.scala
	src/main/scala/concrete/generator/ProblemGenerator.scala
	src/main/scala/concrete/generator/constraint/SumGenerator.scala
	src/main/scala/concrete/generator/cspompatterns/AbsDiff.scala
	src/main/scala/concrete/util/Interval.scala
Merge branch 'master' of https://github.com/concrete-cp/concrete

Conflicts:
	src/main/scala/concrete/generator/constraint/SumGenerator.scala