Clear modX::user on init context

Possible fix for http://bugs.modx.com/issues/10221
fix boolean and numeric values for rendering

empty($params['key']) does not work for string "false"
add the legacy multiple select drop down option
Extending #458 'open in new window' feature with optional Shift modifier. Shift + click in resource tree to edit in new window for users with no middle mouse button (e.g. Apple magic mouse, trackpads, etc)
Reg exp bug
Add margin to input fields

In Firefox, the input fields don't have margins.
Update _help.scss

Adjusting width to account for 1% padding to each box, so 4 boxes are displayed in one row.
Added ability to define "welcome" action & namespace
Better be handled at the controller level (modManagerRequest)
Stick with class parameters...
First step on trying to remove as much as possible duplicate windows (create/update)
Going on with windows "cleanup"
Remove unused "actions" (modAction related)
Media source policy windows + prevent editing a non saved policy (since we can't update its record without ID)
Removed actiondom related assets which seems to be not used anymore
User groups windows cleanup
Remove unused resource group access assets
Context access windows
Quick create/update resource windows
Property sets create/update