Added documentation for On and Extend
Implemented inputDomainSubsetOf
Implemented isEmpty
Implemented Norm(Indices<>)
Implemented Scal*Coll, Coll*Scal, Coll/Scal, -Coll
Added Documentation
Tested a small trinaryIf case with first and second
Implemented trinaryIf for in/output CollOfScalar
Implemented trinaryIf for CollOfIndices
Implemented Gradient
Implemented Divergence operator
Added class CollOfVector based on CollOfScalar
Added documentation for Divergence and CollOfVector
Overloaded a+b, a-b for CollOfVector a,b.
Implemented norm(CollOfVector)