webtest/createTestImage/ for testing

To aid in Selenium testing (and may also be of use for manual testing) use /webtest/createTestImage/ to create a new Image.

Add extra parameters using request parameters, E.g. /webtest/createTestImage/?sizeX=100&sizeY=50

Supported request params (and defaults) are:
 - name (webtest-TestImage)
 - sizeX (125)
 - sizeY (125)
 - sizeZ (1)
 - sizeC (1)
 - sizeT (1) 
 - ptype (int8)
 - dataset (None)   # use valid DatasetID

To test, go to webtest/createTestImage/ - this should create a test image and you will see an image-ID returned. Check in the webclient for a new orphaned image with this ID and check it has the default parameters above.

Now try to add various request parameters from above to the url, refreshing the page each time, to create new images. E.g. /?sizeX=50&name=myImage

Create a Dataset in webclient and use it's ID in /webclient/createTestImage/?dataset=<id>, checking in webclient that the new image is placed in that Dataset.