use the jsEdit generic code for the your-tip widget

Also fixes #2882.
add a "Stop giving" button to the your-tip widget
prune unused function
remove broken logic for restoring the tip amount after signin
fix tests
fix jshint warning
fix homepage JS test
fix is-suspicious on profile pages
remove unused variable
replace the remaining uses of `{% block box %}`
switch title and subhead in `www/%username/account/close.spt`
remove unused variables
add a "fake" mode to `/on/confirm.html` to ease debugging
fix `/on/confirm.html`
simplify markup and styles of `/on/confirm.html`
remove unused styles and classes
fix use of a variable that I removed earlier
fix nav
fix security page and move it under /about