Clean up Crosperf options and help.

Crosperf's help was completely out of date and incorrect.  Fixed
that.  Also, I cleaned up the options, removed some that were no
longer appropriate or not ever used, and made some options global-only.
Also removed all references to pyauto.  We no longer use or run pyauto
tests.

Option changes:  Completely removed outlier_range (it was not actually doing
anything), key_results_only (applied only to pyauto tests), use_test_that
(not needed now that we're not using pyauto) and md5sum (never used).
Made the following options global-only: rm_chroot_tmp, perf_args, logging_level,
show_all_results, board.  Removed 'build' from global settings and made
it an image-only setting (it made no sense as a global setting).

I also adjusted the unittests to work with these changes.

BUG=None
TEST=I tested all the options in all their various positions; I tested with and
wtihout caching; and I tested local and official images.  I also ran the unittests.  Everything works.

Change-Id: I7653663f65c0a3363a1904c0220f1066e72c7f9d
Reviewed-on: https://chrome-internal-review.googlesource.com/160758
Reviewed-by: Bhaskar Janakiraman <bjanakiraman@google.com>
Reviewed-by: Yunlian Jiang <yunlian@google.com>
Commit-Queue: Caroline Tice <cmtice@google.com>
Tested-by: Caroline Tice <cmtice@google.com>
15 files changed