fdo#39468 Translate German Comments - vcl/source/window/dockwin.cxx

(BTW: There seems to be some duplication between dockwin and dockmgr)

Conflicts:
	vcl/source/window/dockwin.cxx

Change-Id: Icaf421620f87de7512a461b778958f6e141946db
Reviewed-on: https://gerrit.libreoffice.org/8171
Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>