New Raster Layer Definitions should auto-select Feature Class

[andrewd]

When creating a new raster layer definition, once you select your Feature Source, Maestro should automatically select the Feature Class and Geometry Property for you - or at least try to. 9 times out of 10, the correct value here will just be "default:default" and "raster". Ideally, Maestro would check available Feature Classes and then automatically select the 1st one, by default- which is how Maestro 1-2.x behaved.

[jng]

Fixed r5973