Bug 5230: Call number ranges in export don't give expected results.

Bug 5230: Call number ranges in export don't give expected results.

If you entered low number and high number, you got only items that *exactly* matched either entry (if any).
If you enter only a low number, you got everying *lower* than that.
If you enter only a high number, you get everything *higher* than that.

This was a greater-than-less-than problem.

Signed-off-by: Nicole Engard <nengard@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>