Add projections for the element-wise multiplication

[matthewcrews]

Add some quality of life operators and features:

1) Extend the .* operator to handle SliceMaps of different dimensions.

For example: SMap<'Key,'Value> . SMap2<('Key1, 'Key2),'Value> SMap<'Key,'Value> . SMap3<('Key1, 'Key2, 'Key3),'Value> etc.

2) Add the ability to "ReKey" a SliceMap to change the order of the dimensions in which the values are stored

3) Add the - operator to the Domain and SliceMaps

[matthewcrews]

Did not add subtraction to SliceMaps. Upon review, it didn't make sense