introduce transform module
avoid using 'transform' for variables
use transform.Scale when possible
change Cascade to give transformations i/of points
simplify Transform using new Cascade
cache point transforms, summarize cache effectivity
add cache summary to elem_eval
streamline StdElem derivatives
remove unused TrimmedIscheme
major element overhaul + reimplemented trimming
fix triangle edges, children
move triangle edges, children to constructor
tensorize quad elem, edges, children, trimming
transpose Simplex.vertices
change triangle conventions, first point in origin