Check for missing resource_path property
Simplified code
Ensure project admin URLs are matched

Conflicts:
	pootle/apps/pootle_project/urls.py
Fixed stupid caching mistake

Conflicts:
	pootle/apps/pootle_project/models.py
Cleanup: make code more readable
More flexible way to customize behavior for each drop-down
No need to determine the initially-selected value

This is already done in `PTL.browser.fixDropdowns` when the `pageshow`
event fires.