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