fix a bug in acl manager where it attempted to correct too high page permission levels using the wrong var

Populate global variable JSINFO also in the Media Manager popup

lessified pagetools items, added mixins simplify maintenance

fixed old pagetools sprite loading from cache when hovering

translation update

Re-enable displaying the date in the revert manager (Fixes FS#2073)

Extension manager: Implement extension table

This uses a lot of code and the whole design from the previous extension
manager implementation.

style improvements

enable email notifications & alert messages for imported users

removed a merge conflict I missed on merge

added basic suport for embedding (html5) videos

de/de-informal/en: Removed redundant suffixes in TOC of configuration
manager / Synchronize terms in de and de-informal

check less compilation for errors

This now gives proper files and line numbers for errors

improve html structure and styling for add & edit user notes

made necessary by PR#254 which adds content below these notes.

usermanager: fix an issue where edit user table would incorrectly show the password blank message

add csv import functionality to the user manager

de/de-informal updates: Replace "Nutzer" with more common word "Benutzer"
/ fix several typos / Fixes FS#2821

Enable LANG.template.<template>.key to provide localized strings in templates

Extension manager: implement uninstall, canModify and install/update

Extension manager: Improve update check

Extension manager: Use getInfo() when no info.txt is available

Extension manager: fix install dir for templates

small fix for pagetools in RTL languages

Revert "translation update"

This reverts commit d6d855093f24c6c3f608d005189385959a7efbf7.

I guess it was a bit too early to think straight :-/

translation update