add test for profiling, never aborts
remove applied_MVN benchmark for now, as MVN::set() and related functions will be removed
add base class for version tracking of two inputs
reduce ndims to 100 to allow for tests to pass quickly
add base class for version tracking and caching of one input
add base class for version tracking and caching of two inputs
modify all classes so they inherit from the VersionTrackers

breaks tests because of multiple copies not being all updated