[MERGE] specify range_offset_limit per pattern

These modifications allow the user to specify multiple
range_offset_limit lines which will be matched per a specified pattern.
These patterns work the same as the ones for refresh_pattern, and will
accept the same -i modifier. The lines are parsed from top to bottom,
using the first matching line (just like acls). If there is no
range_offset_limit line that matches a particular request, the default
of 0 is used.