ENH: run_order option for BenchmarkRunner with "multires" support

If there is a bulk of commits to benchmark but it is desired to review
global trends asap it would be worth to traverse the revisions in order
increasing temporal detail.  multires option for run_order would do precisely
that.  See docstring for multires_order function
ENH: use logging (with fancy formatter: color, multiline logs indents) + unified run_cmd + minor tune ups

Some kind of clean up must happen before every checkout, since some stale files
might be in place and prevent a checkout.  In general cleaning up .py[co] might be
insufficient if extensions are generated as well

Logging -- coloring is enabled by default unless some of the in/out's doesn't have
a TTY.  Seems to work quite neatly.  By default produces all the output, including
DEBUG, but now much easier to parse.  Also added few more new logging messages.
Timestamping is handy whenever the whole process hangs somewhere and it is desired
to retrospect later on
Merge pull request #30 from yarikoptic/enh/logging_and_running

Enh: logging and running