3 Minor annoyances fixed
* subprocess is now grabbing properly stderr (was not working in python2.7)
* only the first line of the error message by coffeescript is logged (the rest was nodejs trace)
* when a coffee file does not compile, hash is now voided properly & resulting .js deleted to avoid stale copies of the generated js to polute
Fixed error when trying to delete a file that does not exist.
Merge pull request #1 from cajun-code/master

Found an issue with trying to delete a file after a failed compiled.
Merge remote-tracking branch 'arnaudsj/master' into arnaudsj

Conflicts:
	plugin.py