Cache mark locations during a single run of the parser
Make tokenizer emit line/ch positions as well as offsets (not used by parser yet)
Use positions from tokenizer in parser. Mostly working but one unit test is failing.
Breaks HTMLInstrumentation into three files.

HTMLInstrumentation: handles the interface between editor/document
and live HTML.

HTMLSimpleDOM: Parses HTML into a simple DOM-like structure with
properties useful for HTMLInstrumentation.

HTMLDiff: Generates a list of edits to mutate a Simple DOMs into another.
Only create marks for tag nodes
Wrap operation around mark update
Avoid destroying and recreating marks that haven't changed
Merge branch 'adobe-nj/LiveHTML-perf' into dangoor/LiveHTML-refactoring

Conflicts:
	src/language/HTMLInstrumentation.js
Naming cleanup as suggested in review
Remove unused signatureMap
Merge branch 'master' into dangoor/LiveHTML-refactoring