Removed the R not found message box from the initialization
routine.

This was happening outside the applications main event
loop and causing things to permenently hand.
Added Three band rasters to the output options
Fixed bugs where 1.2 prerelease
session folders would not open
in 1.2 final
A couple of minor bug fixes
Changed block size and algorithm to check if we
need to use the efficient background selection
method.
Fixes Jira 206
Deviance not showing up when subfolder selected
Fixed bug where singleton PARC inputs
not running
Fix for aggregation breaking on large
rasters