revset: added min and max methods to baseset and lazyset This classes have no particular order so they rely on python min() and max() implementation. This methods will be implemented in every smartset class in future patches. For other classes there are lazy implementations that can be made for this methods.

contrib: make revset benchmark script able to read from stdin This help fine control of what we want to benchmark

contrib: have the revset benchmark test script take a revset The script now selection revision to run benchmark against using a revset query instead of a revision range. It is expected that people benchmarking revset have some knowledge of revset.