Fix buggy autocomplete behaviour for non-US keyboards

This change moves the code for actually entering data from the keydown handler to the
keypress handler, which can reliably catch the character entered (rather than
the key pressed).

This is my second attempt at
https://meta.discourse.org/t/typing-shows-on-non-us-keyboard-layouts/20449
without doing dangerous refactoring.

This does not fix the issue reported in
https://meta.discourse.org/t/overly-aggresive-emoji-autocomplete/20691/7
as that is a different bug.
FEATURE: ensure consistency of post revisions
FEATURE: CORS settings per-site in a multisite env
FIX: ActiveRecord error when calling `find` for the topic list key.
FIX: Deprecation warnings on `webkitIndexedDB`
Let's try telling uglifier to user 1k lines
Fix uglifier args
Check if `Uglifier` is defined (we're precompiling assets)
Don't specify uglifier in dev
Add `screw_ie8` setting
update onebox to latest version
Let's try to change Uglifier settings properly
FIX: Symbol was missing colon
cache breaker for new uglify options
FIX: use overflow:hidden on reply expansions
remove another lightbox 100% width hack
slight copy simplifications. Omit Needless Words
FIX: migration would break if locale was forced to french
reduce number of times caretPosition() is called
Merge pull request #2871 from mamhoff/autocomplete-again

Fix buggy autocomplete behaviour for non-US keyboards