Clean up some quotes in template tags
Disable automatic password hiding with ?plain parameter
Add link to disable automatic password hiding
Javascript: Extract methods
JS style: Add semicolons
Make ?plain work when JS is on
Update README
Add JSON export script
Update "invisible copy" feature.

Works around https://support.mozilla.org/en-US/questions/977068#answer-500083
(writing to clipboard is no longer possible) by creating
and invisible <input> the user can Ctrl-C from.
Invisible Copy: Add hint via title tooltip