As discussed on riot, turning noiframeon into a site-specific setting
is a good thing for consistency. This commit also adds a deprecation
warning when users try to `:set noiframeon` and updates the
troubleshooting guide.
The try/catch in init() prevents errors from bubbling up and thus
also prevents the document.addEventListener("DOMContentLoaded", init)
call from being performed. We fix this by removing the try/catch from
init() and adding a new one in the document.addEventListener call.
This commit fixes the command line not appearing on
https://www.haiku-os.org/docs/HIG/index.xml. The problem was that
document.createElement uses the namespace of the current document, which
for the haiku-os page was a docbook namespace. This caused the created
iframe to have default docbook attributes and none of the regular html
ones (e.g. contentWindow).
Closes https://github.com/tridactyl/tridactyl/issues/1165 .
