If there are x:cfRule's and x14:cfRule's with matching
range-list, then insert the conditional-fmt entries into
the document in the order of the priorities. That is
don't just append the x14:cfRule entries to the document
after the x:cfRule entries are inserted.

There was also a off-by-one bug in the priority export
of x14:cfRule entries. This caused the priority numbers
to be duplicated. This is also fixed.

Change-Id: I5b0d11c4456b2966b808f6ee589075a870f43768
Reviewed-on: https://gerrit.libreoffice.org/71311
Tested-by: Jenkins
Reviewed-by: Andras Timar <andras.timar@collabora.com>