various gui fixes

added connectivity recheck

fixed typo in define

fixed screenshot height

added tabURL builder

translation update

FS#2806 - fix auth capability listing in html_debug()

translation update

change 'debug' setting to 'security' (rather than 'danger')

convert from iso-8859-1 if not utf8

add 'danger' alert to authpgsql config settings

add 'danger' alert to authmysql config settings

add 'danger' alert to authldap config settings

add 'danger' alert to authad config settings

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

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

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

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