[Test] Update touch_firmware_versions script.

Check in my local changes.  This includes:
- Handle reef-specific changes.
- Refactor code to use a firmwareInfo class, instead of just printing.
- Minor regex improvements, including allowing .hex filenames.
- Clean up a few logic errors that don't cause trouble with existing
ebuilds but could in the future.

BUG=None
TEST=result output does not change (except sorted and has reef changes)
Change-Id: Ib089b891ab13e8a5effc5071551daeee4924c8a5
Reviewed-on: https://chromium-review.googlesource.com/617511
Commit-Ready: Katherine Threlkeld <kathrelkeld@chromium.org>
Tested-by: Katherine Threlkeld <kathrelkeld@chromium.org>
Reviewed-by: Vinayak Suley <vsuley@chromium.org>
1 file changed