Typo fixes and non-code tweaks

Skipped replacements:
* prefered → preferred
* prolly → probably

Skipped files:
* resources/lib/jquery.ui/jquery.ui.mouse.js
* resources/lib/jquery/jquery.form.js

Change-Id: Ib7923f362ddfca1b892bf5d601785d6b5aa5d44c
Merge "Typo fixes and non-code tweaks"