[#9129] Add refreshURIs call as part of clearing the site cache
Adding event to the middle mouse button click.

This is a continuation of https://github.com/modxcms/revolution/pull/449 in another realization. 
And prevent changes in the current window
Error property added plus getter and checker for it
modError is instantiated when sending fails
Error getter renamed
Fix unescaped backslash in file and image TV

Fix for #9526: http://tracker.modx.com/issues/9526
Clear modX::user on init context

Possible fix for http://bugs.modx.com/issues/10221
Add upload functionality directly to package manager grid
remove commented-out line for ocd
Add new processor to allow custom core_path location
Restrict upload to zip only, and switch to new processor
Modified getTree() to support options (like context) as getChildIds()/getParentIds()
Added OnElementNotFound system event
CSS Twerks

Un-uglifying the required/invalid input state (now uses red border and
font awesome icon)
Adjusting x-panel table header hue (to $darkNeutral)
removing legacy green buttons in package manager (now $primary)
retina-tizing x-btn-split (Download Extras button)
uberbar result hovers (%nav-item)
Help Page Improvements

Retina CSS MODX Help Logo
Primary Action styling on sign up button
Fix error with package management caused by #691
Add preg_quote to friendly_alias_word_delimiters characters

This allows you to add / as a friendly_alias_word_delimiter without breaking the regex
- Show events on new plugin page
- reverted last commit, as already fixed