Refactor the code a little to make this easier to munge around.

By default don't re-run tests that have already run successfully, to
reduce latency between making a change and seeing if it fixed the last
thing that you were trying to fix.

 -) Fixing long line length.
 -) Changed the logic of the exit message.

  -) Adding a new command line flag to be able to see which tests are passing.
  -) Adding more status when the tool is idle in forever mode.
  -) Adding a last status when the tool is finished so to avoid leaving the console in a weird state.
  -) Adding a status message in the forever mode if the previous run failed.
  -) Swapped the message and its explanation, so you don't have to scroll up to see which test failed.
  -) Fixed a race condition in the watch_dir.py code if a file is deleted during the loop.

If openssl has not been built, running parallel make processes causes some problems.
	Change on 2015/01/09 by ctiller <ctiller@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83617340

	Change on 2015/01/07 by ctiller <ctiller@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83451760