add method to load assets package build contents

makes it possible to use scss in mails

TODO: correctly work together with ccw
fix package getBuildContents
text changes
OptBox: Fire cookieOptChanged and listen to optChanged in OptComponent

This way optBox changes also change checkbox of OptComponent and change
of OptComponent checkbox hides OptBox.
Merge branch '3.7' into 3.8
OptComponent: hide submit button via css, not js

Shouldn't be needed because every tracking only works with JS
Remove styling not needed because of display:none
Merge remote-tracking branch 'origin/3.7' into 3.8
selector on error-simple mixins are too exact
don't overwrite field value with placeholder value
deleted user password validator from double password field

forms should add this not this field
form mixin - when you set params to false they are deactivated
added user password validator on first password field
use correct params format in construct for zend string length
ugly workaround: don't include Frontend dependency directly in admin, use own file

Works around ~4000 selector limit of IE8.

TODO: find proper solution
fix for previous commit: javascript doesn't work correctly anymore if split Admin/Frontend

hack even more to split only css
add hidden config for set password success because it uses activate succes
OptBox: Fire optChanged event after save-request has completed

Else server-side cookie isn't set when optChangedController is called
Merge branch '3.7' into 3.8
make _mail protected so we can change from field