Feature: tools: new tool to compare crm_simulate profiling output

pcmk_simtimes is not installed or distributed, since it is only useful for
comparing two different Pacemaker builds and thus developer-targeted.

There seems to be a fair amount of variation from run to run of
crm_simulate profiling (for the same build), so it's unclear at this point how
much of a difference is significant. But this should help highlight whether the
overall trend is positive or negative.

% pcmk_simtimes ~/crm_simulate.out.master ~/crm_simulate.out.devel -s 0.1 -p 5
clone-order-16instances 10.51s vs 11.10s (+0.59s = +5.61%)
group4 0.67s vs 0.80s (+0.13s = +19.40%)
notifs-for-unrunnable 17.12s vs 18.60s (+1.48s = +8.64%)
migrate-5 0.88s vs 1.04s (+0.16s = +18.18%)
migrate-stop_start 0.95s vs 1.05s (+0.10s = +10.53%)
(etc.)