set MANUAL_AUTH_URL to Bareos documentation

the provides URL has been wrong. Replaced to working documenation URL.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>
removed unused or outdated translations

removed files that do not contain any translations,
removed translation that are outdated,
removed outdated informations from README

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>