Better default for pager limit

When exposing the pager limit in search and -All- results is selected, facetapi returns a pager_limit of 10, so current search blocks will say "Displaying 1 to 10 of 473 items" instead of "Displaying 1 to 473 of 473" items. In looking at the code it looks like the 10 is a default value if the pager global is not set. I am thinking there might be a better default - patch to follow.