Fix #824 "Setfocus on XBL with mode="focus" focuses on nested control"
Fix #825 "Recaptcha doesn't work anymore"

- use XBL focus, binding and lhha modes
- fix search for input field
- remove hack for validity
- use jQuery
- improve CSS
- small clean-up
Fix fr:simple-captcha

- use XBL focus, binding and lhha modes
- fix namespace declaration
- improve CSS
FB: Edit Source: don't allow empty text