fix: compiling `coffee.coffee` produces `.js` file.
more test coverage for `baseFileName` helper.
tests for `baseFileName` helper for files with only coffee-script extensions as the file name.
Merge pull request #2795 from fahad19/master

Fix: compiling `coffee.coffee` produces `.js` file.
merge
Fixes #2781, fixes #2782. Reverting to old method of instance method binding.
Add an additonal test, courtesy @matehat
Fixes #2796, by adding a test for it.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	lib/coffee-script/helpers.js
	test/helpers.coffee