New version of the bbh shootout.

New version of the bbh shootout.
There were a bunch of problems with the existing code, all of which I would of ignored, except it could only benchmark none and rtree.
The new version measures the same numbers, in almost exactly the same way, it's the structure over the top of the actual test runner that I changed.
Now it only loads the pictures once, it is configurable in which bbh's it runs and how may loops on them it does, it uses standard command line processing, and it does not do so much redundant work so it runs quicker. It is also much easier to understand and change IMHO.

Doing this so I can reasonably compare the new QuadTree implementation.
BUG=skia:2242
R=tomhudson@google.com, mtklein@google.com, reed@google.com

Author: iancottrell@google.com

Review URL: https://codereview.chromium.org/186973005

git-svn-id: http://skia.googlecode.com/svn/trunk@13736 2bbb7eff-a529-9590-31e7-b0007b416f81