cmdutil: changed max method for lazy call Used the lazy max call instead of the python max implementation to be able to use lazysets for graphlog.

getgraphlogrevs: return an empty baseset instead of a empty list We aims at returning smartset only so that function higher in the stack can use smartset feature.

getgraphlogrevs: do not convert smartset to baseset We are now sure that revs is a smartset. We remove the baseset call that would defeat any lazyness.