If we want to filter away a column without changing the filtering
for the rows calling invalidateFilter() is wasteful because it will
call filterAcceptsRow() for all rows even though that is not needed.
This commit add two functions, invalidateRowsFilter() and
invalidateColumnsFilter() that work the same way as invalidateFilter()
except that they will invoke respectively only filterAcceptsRow() and
filterAcceptsColumn().
Change-Id: Ib4351cf08c229bd97bbbfee6da92397dca579a84
Reviewed-by: David Faure <david.faure@kdab.com>
b5f6a85d27