Toggle: add onbeforeprint behaviour

1. Allow a toggle element to turn the elements it controls
   on/off when the page is printed.
2. Update the working examples with the new "print" option.
Toggle: add unit tests for onbeforeprint
WET theme: Ensured that the active area for the menu button in small view is 50% of the header width (fixes #4181)
Merge pull request #4182 from pjackson28/fixwetthememenubutton

WET theme: Ensured that the active area for the menu button in small view is 50% of the header width (fixes #4181)
Merge pull request #4179 from patheard/onbeforeprint

Toggle: onbeforeprint behaviour