Re-adds prematurely pushed Crop2D classes for local dev.
Implements basic Crop2D operation, no null handling
Moved actors to own plugin.
Abstracted graph running and exportation to extension points to reduce connectivity.
Functional 2D crop. Code needs a bit of pruning and problem if two indices are same.
Merge branch 'master' of ssh://dascgitolite@dasc-git.diamond.ac.uk/scisoft/scisoft-core.git

Conflicts:
	uk.ac.diamond.scisoft.analysis.processing/plugin.xml