Responsible for the acquisition of all projections for a focus. See 
load(OperationResult) method.
 Note: full resource objects are not loaded in this class (now), except for:
 1. when they need to be classified - see 
ProjectionContextKeyFactoryImpl.createKey(ShadowType, Task, OperationResult),
 2. when a conflict needs to be resolved - see 
ProjectionsLoadOperation.ShadowLevelLoadOperation.treatContextConflict(ShadowType,
 ProjectionContextKey, LensProjectionContext, OperationResult)
 For full shadow loading, see 
ProjectionUpdateOperation (for reconciliation)
 and 
ProjectionFullLoadOperation (for ad-hoc full shadow loading).
 *BEWARE*: Removes linkRef modifications from the primary delta, if there were any. See 
removeLinkRefModifications().
 TODO better name for the class?