Make sure that newly added layers are a sensible size

[Peter Parker]

Try adding a new layer to an existing plot using the following instructions:

http://www.mantidproject.org/MBC_Displaying_data_Complex

Unfortunately, to get the titles of the two layers to align like they do in the image, you have to adjust the sizes of the layers manually.

It would be nice if the "add layer" functionality was clever enough to see what size layers are there already, and just use that size.

[Nick Draper]

bulk move to assigned at the into of the triage step

[Stuart Campbell]

This ticket has been transferred to github issue ​9297