support use of disable-with on elements using the "form" attribute
extraneous commented line
refactor form element selection into helper function
Merge pull request #366 from twalpole/form_attribute

support use of disable-with on elements using the html5 "form" attribute
Merge branch 'master' into data-disable

Conflicts:
	src/rails.js
	test/public/test/data-disable.js