Fix #1477 "Namespaces lost in Publish to Production"

This is more of a workaround at this time. It's unclear if the original issue is due to Oracle messing up namespaces, or whether the problem is within Orbeon Forms itself.
font-family: match bootstrap, use variable if possible
More xf:valid() and xxf:valid() -> valid()
Edit Choices dialog: enter doesn't work in hint field