Test update for resolved bugs
[lib.d.ts] Add Document.createEvent specialized overloads
initial rev of cancellation
cancellation checks in fourslash
getReferencesAtPosition API: renaming does not find all methods
Don't create missing tokens when a user legally elides a semicolon in their code.

This helps with formatting as well as with incremental parsing.
Updating fidelity tests.
Remove unused variables.
Update Win8 sample to target Win 8.1 (so it loads in VS 2013 without a warning).

And remove references from files and .js files from project to match latest project system conventions.
Simplify incremental parser.

Simplify logic for our synax cursor so that it can avoid costly array manipulations.
While the javascript Array API is quite rich, the implementations seem to have an
(understandably) difficult time providing fast access across many interesting operations
(like shift, unshift, splice, etc.)

We now just keep a true cursor and use that to keep track of where we are, updating
accordingly in a simple manner.
TypeError: Unable to get property 'type' of undefined or null reference at getImplementorsAtPosition
Cache the current token and node that the parser is looking at instead of always recomputing them.
Updated harness.
Remove unnecessary functions.
Simplify parsing code.
Remove need for parser to keep track of the previous token.
Improving incremental parsing perf.
Speed up parsing by not realizing trivia for keywords that are converted to identifiers.
Cache change range span for perf.
Don't null out the cached span.