AUTH_PASSWORD_GENERATE event added

This is needed to replace the password generator by a plugin
implementation. Related to PR #166 and FS#2147

fix problem when ldap returns no groups FS#2788

fix ldap deref option FS2798

Do not pass timelimit and deref settings to ldap_search. These values
should be set globally via ldap_set_option() instead (as we do for
deref).

treat empty AD credentials as NULL values FS#2781

Korean language update

fixed references from old mysql authtype to new mysql plugin in mysql.conf example

fixed broken default config options (FS#2789)

updated dates in templates' and plugins' info.txt files

Japanese language update

Czech language update

Russian language update

Japanese language update

authad: capabilities depend on userdomain specific config

authad: added compatibility for old option names

adLDAP renamed the ad_username and ad_password to admin_username
admin_password recently. this makes our backend recognize the old
settings

authad: don't request empty fields

fix expiry check for adLDAP version FS#2759

Japanese language update

fix ids in de lang of authAD

de/de-informal: Change "Vorlage" to "Template"

de/de-informal: Re-add TOC suffixes (Will be removed after the release
again)

de/de-informal: Re-apply the updates of ba09710ad34bb383ae3526e84490a3d545f78866

Rename ad_username to admin_username
canDo getUsers to false when unavailable

Revert "German language update"

This reverts commit ba09710ad34bb383ae3526e84490a3d545f78866.

Conflicts:
lib/plugins/authad/lang/de/settings.php

adjusted authad language files for config option change

LDAP: do not bind anonymously if superuser is set FS#2607