Coordinate transformation on single RVecs

Coordinate transformation on single RVecs

So far, coordinate transforamtions of TranslateAndScale and Scale
classes could only performed on ArrayRefs. This meant that
transformations of single RVecs had to be done by first constructing an
ArrayRef on a single RVec x with the unintuitive and cumbersome
transform({&x,&x+1}).

Now this call is reduced to transform(&x) and respective calls.

Change-Id: I0d1f9d2f5ba90a46b1afc9b617af606995e0df59