Insight ui testing 11210

Seems we have enough working tests to consider merging back to dev_4_4.

This PR is on top of Mark's - Just focus on web stuff for this PR.

Set-up:

```
$ pip install robotframework
$ pip install robotframework-selenium2library

# Need this for my Python robot framework extensions
export PYTHONPATH=$PYTHONPATH:<OMERO_PREFIX>/components/tests/ui/library/python/
```

Currently I'm running tests like this:
```
$cd components/tests/ui/testcases/web
$ pybot --loglevel debug examples.txt
$ pybot --loglevel debug image_test.txt
```

However, this creates a bunch of output logs, images etc in the current dir, which could be improved.