Problem Description:
- Matrix multiplication cell formula range is not exported after roundtrip.

XML Difference:
Original : <f t="array" ref="G5:G6">MMULT(A1:C2,E1:E3)</f>

Roundtrip : <f aca="false">MMULT(A1:C2,E1:E3)</f>

Solution : Added formula cell range support for matrix multiplication.

Change-Id: Ic871f064a98a324bc16a4253b633c97417c3f900
Reviewed-on: https://gerrit.libreoffice.org/16033Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>