Shifted more functionality to sanitize

Moved attribute filtering, replaced calls to forEach/reduce/filter with
native array method calls, moved some reg exp declarations outside of
functions (invariant), improved attribute filtering to accept a map,
added default map of removable attributes, used better function names
for removing attributes (stopped using filter in the Array sense)
Shifted unwrapping from calamine into sanitize

Mutation belongs in sanitize. Unwrapping is compression and not related
to boilerplate analysis. Also uncovered a bug with unwrapping. Also
deprecated unused functions in calamine.
Simplified type bias

Renamed nameBias to type bias, created a separate map for type bias and
moved information out of the policy map
Deprecated element policy

Split up last remnants of element policy into ancestor and descendant
bias maps. Removed leaf check from applyTextScore. Fixed density calc
bug in applyTextScore (now allows for undefined anchorCharCount).