Improvement to suitability modeler UI

[DuncanHornby]

In suitability modeler, when inputting weight percent values, allow the interface to use the standard CRTL+A (select all) and CRTL+V (paste) key strokes.

Currently you have to click in, manually delete the existing value, then type it in.  If one is using the Assign weights by pairwise comparison tool you ultimately want to pass in those weight values and the quickest way is to click into the weight box, select all and type in the new weight