Added toarray to cubic, to produce a 3D array representation of the network
Some housekeeping
- Renamed Tools to Core
- Moved Core and Base to main OpenPNM directory, rather than under Utilities
- Moved Harolds files to Utilities
- Moved the subset methods from GenericGeometry to a Subsets file in Utilities
- Also updated them to work again
Minor cleanups
- Added a 'pore.map' and 'throat.map' property to the Geom and Phys dictionaries during init
- These list the pores/throats in the network that correspond to the local pores/throats