and unused using-declarations from Reference.h

Change-Id: I297a7ae6044fa329d245ecf08fd5c4cb930f5b19
Reviewed-on: https://gerrit.libreoffice.org/23735Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>