Add check for empty --file argument before running run-tests.sh during simpletest reviews

Patch attached.

Well ... that didn't work. New approach.

Merged this patch into the one posted at #1126112-11: Full tests of Drupal being done for some contrib patches, as they would otherwise conflict.

Fix committed in referenced patch.

Patch reversed, as the 'fail' condition prevents the ability to leverage testbots to ensure a patch can be applied against a project with no tests.

New approach, which should catch 'No tests found' due to testbot errors, but will not execute run_tests.sh if no arguments are found for the '--file ' parameter.

After more thought, this won't actually catch the 'no tests found' error ... but is still a step in the right direction.

Posting patch here so I can validate on scratchtestbot ...

There ... I think this does the trick.

This patch takes the following approach:
i) Check for empty arguments on the "--file" parameter, and skip run_tests.sh if there are no tests to run
ii) Scan the review output for "PHP Fatal error", and fail the test if one is found ... thus fatal errors which interrupt the review process do not result in 'green' results.

This check could possibly be extended to include PHP Warning ... but I think the 'Fatal error' version this should catch 90% of our problem cases now.

Looks promising ... tests result can be found at:

zero tests passed: http://rfay.redesign.devdrupal.org/node/1073590/testing-status
PHP Fatal error: http://rfay.redesign.devdrupal.org/node/19304/testing-status (6.x-1.x)
With actual tests passed: http://rfay.redesign.devdrupal.org/node/19304/testing-status (7.x-2.x)

Rerolled patch.

Committed to 6.x-2.x (264fb4f).

Couldn't find a patch which contained a FATAL but didn't break the testbot, so that component of the patch is unproven. Will need to watch for this scenario after deployment.