Validate '|' cannot be in a password

http://manage.dimagi.com/default.asp?60104

Monkey patches set_password. Displays "'|' is not allowed in a password" as the error in all three possible locations.
I agree about the font.

I thought about the these characters are what we allow message, but then since this is the only character we don't allow, it will have to be a very long string and would be fairly ugly.

Validation should happen client and server side, since client side validation could be changed by a client in the console. Not sure why anyone would want to do that.

May not need to put this fix in anyways depending on outcome discussed http://manage.dimagi.com/default.asp?60104.