Split guzzle.coffee into separate files

* Upgrade the gulp-sass lib to 0.7.2
* Add "gulp" as a global in the tests
  (because the "fingerprint" method needs to access it,
  and running the "gulp" command adds it as a global)
Split test files

* Rename "spec/" to "test/"
* Change "-spec.coffee" to ".test.coffee"
* Move fixtures outside of "test" to "test-fixtures" (otherwise mocha tries to run the
  fixture files)
* Add mocha.opts file and shorten the package.json mocha commands
  (now you can just run "mocha" or "mocha -w" to run the tests)
* Fix the jade2html test to check for basePath handling.