[Speed] perf module 0.7 released

[Victor Stinner]

Hi,

I released perf 0.7 (quickly followed by a 0.7.1 bugfix):
http://perf.readthedocs.io/

I wrote this new version to collect more data in each process. It now
reads (and stores) CPUs config, CPUs temperature, CPUs frequency,
system load average, etc. Later we can add for example the process RSS
peak or other useful metrics.

Oh, and the timestamp is now stored per process (run). Again, it's no
more global. I noticed a temporarely slowdown which might be caused by
a cron task, I'm not sure yet. At least, timestamps should help to
debug such issue.

I added many CPU metrics because I wanted to analyze why *sometimes* a
benchmark suddenly becomes 50% slower (up to 100% slower). It may be
related to the CPUs temperature or Intel Turbo Boost, I don't know yet
exactly.

The previous perf design didn't allow to store information per
process, only globally per benchmark.

perf 0.7 now supports much better benchmark suites (not only
individual benchmarks) and has now a really working --append command.
A benchmark file has not enough runs? Run it again with --append!

Changes:

* new "pybench" command (similar to "python3 -m perf ...")
* the --append is now safer and works on benchmark suites
* most perf commands now support multiple files and support benchmark
suites (not only individual benchmarks)
* new dump command and --dump option to display runs
* new metadata: cpu_config, cpu_freq, cpu_temp, load_avg_1min

In the meanwhile, I also completed and updated my fork of the CPython
benchmark suite:
https://hg.python.org/sandbox/benchmarks_perf

Victor