Change the Sizzle module to pull sizzle.js from /dist rather than /src. [close #194]
Ensure that Sizzle loads properly in RequireJS or CommonJS environments.
[close #203]
Temporarily move the new unit tests while I shuffle things around.
Shuffle the unit tests around (step 2).
Remove the old unit tests.
Make the new testing tasks the defaults.

NOTE: We are getting rid of the caja:test task because I do not believe it is used anymore. If I am wrong, please let me know.
Some comments and cleanup.
Make `PrototypeHelper.require_phantomjs` work properly on Windows.