Major refactorings. Unstable.

* OpenXLSWorkflow.fs: Removed unused code and passed delegate to
  TryOpenVPP that sets the events for PartitionerWorkflow

* PartitionWorkflow.fs: removed unused code made events C# compatible
added Error alert to handle when a name has invalid characters
renamed Partition method for WriteToXLS and moved write function to be
  included in the method.
refactored measure function for correctness