These source files relied on pch to include
these missing headers (at least on Windows).

Also included the script used to find the
missing includes. The script is self-contained
and includes unittests. It detects superfluous
includes and required includes (which was used
to restore the includes in this patch).

Change-Id: I7ee09e5c712f42d5f6c3524898bc62dda78f5cc0
Reviewed-on: https://gerrit.libreoffice.org/18208Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>