debugwalk: pretty-print nested matcher While porting filesets to composition of matchers, I found the original one-liner was hard to read.

debugwalk: show matcher output only if -v/--verbose And drop "egrep -v". This matches the behavior of "hg debugrevspec".

stringutil: promote smartset.prettyformat() to utility function It will be used by debugwalk.

profiling: introduce a "profiling.time-track" option This option allows to switch the time used by the statistical profiler from cpu to real time. Our goal is to profile IO intensive operations using the mercurial profiler.