Update OpenAustin.html

Switched google groups signup form to wufoo form
Update OpenAustin.html

Added copy adapted from Open Austin website
Update OpenAustin.html copy and link to wufoo interest form

Copy adapted from open-austin.org. Wufoo form created at 05132013 hack night.
Merge branch 'master' of github.com:khit/atx-civic-tech-expo-demo into khit-master

Conflicts:
	html/OpenAustin.html
	src/pages/OpenAustin.rhtml