lfs find should send getattr on mds only if needed;
lfs find should not break on matched obd but check other parameters as well;
lfs find compare fixes:

• size +N is supposed to find files larger than N, equal size is not included;
• ! size -N is supposed to find files larger or equal N;
• size units are to be initiailized to 1 if none is specified (K|M|G) to find the proper region;
• file type should not be checked twice, but instead to be checked if not yet;
• return value from previous time checks in find_time_check() should not screw up another check;