Enhance squish refl tests

[Owen Arnold]

Squish test enhancements for the reflgui. I've thought about ways to provide a few more tests, which a good ability to pickup defects. Continuing with the existing mantra, I only want to test what can't be tested via unit tests, I only want to test areas that are commonly used, or easily broken.

1) Update the squish tests to fail if we end up with orphaned TOF input workspaces. Since removal involves a naming convention, it's really easy to get into a state where a small change results in intermediate workspaces being kept.

Squish tests should fail unless all output workspaces in the workspace list can be accounted for.

2) Have a test which checks stitching as this is commonly used

3) Have a test, or retrofit existing tests to check the availability of the plot button

4) Have a test which checks auto population of theta if a 3rd run is provided. This currently has absolutely no test coverage.

[Owen Arnold]

refs #10207. Check for orphaned workspaces.

This actually only really needs to be done for the first test case. I've also cleaned up some of the output messages to make them more accurate and easier to read from the test outputs.

Changeset: 5eb8853f6789483a48fbb297129d5059e4bd7461

[Owen Arnold]

refs #10207. Remaining tests.

Changeset: 0ead94d9aaf8feaa171d59ea083a775a86d321f0

[Owen Arnold]

Tester. This is very simple to check. Just check that 25 tests should not be running ​http://builds.mantidproject.org/view/Develop%20Builds/job/develop_squishtest/

[Harry Jeffery]

Merge remote-tracking branch 'origin/feature/10207_enhance_squish'

Full changeset: ​cd3f1e0a551ec81c954ea3f8366d319afa478481

[Stuart Campbell]

This ticket has been transferred to github issue ​11049