Changed raise Exceptions into _logger.warning messages.
Added super cool awesome 'subset' method.  You send in a list of pores from the current network and it returns a new network of those pores.
Final touches on 'subnet'
- When the method is called it not only returns subnet to play with, but also puts labels in the main network indicating which pores (and throats) correspond to which pores in the subnet.
- See the doc string on the 'subnet' method for more details, but basically pn.pores(sn.name) gives the list of which pores in the main network were used in the subnet work.
Merge branch 'develop' of https://github.com/PMEAL/OpenPNM into develop

Conflicts:
	OpenPNM/Network/__GenericNetwork__.py
Add two @property methods: Np and Nt.
- These just call the num_pores() and num_throats() methods, but require no typing and no arguments.  They are simply for convenience and less typing.
Added Np and Nt @property methods to GenericGeometry
Updated the __repr__ method in base...I was getting tired of the objects subclassed from dict spewing out all their data on the command line.  Now all object print their basic info when you enter >>>pn
Updated many docstrings in GenericNetwork
Added two new methods to GenericNetwork: 'fluids()' and 'geometries()'.  These work similar to the props and labels methods=:
- If no arguments are given, it returns a list geometry or fluid objects associated with the network.
- If a 'name' is given, it returns a handle to the object with that supplied name
finished some documentation in the conduit_conductance method.
Added count to GenericGeometry.  This now means that the number of pores in a geometry can be found with all the same tricks as networks and fluids (Np,Nt,num_pores,num_throats, and now count)
- This was basically cut-and-paste, but it's only a few lines so not worth figuring out how to inherit it
Merge branch 'develop' of https://github.com/PMEAL/OpenPNM into develop
- Added pore/throat counting methods to GenericPhysics
- GenericGeometry and GenericFluid now have 'physics()' to find the associated physics
Fixed bug in the 'subnet' method...moved the definition of 'pore.all' and 'throat.all' higher up so that they were available when the other data were set (__setitem__ uses these to compare array sizes against)
Experimenting with subset_fluid method...this seems necessary so that simulations can be run on the subnets, but there may be a better way.
Updated OP documentation, and changed it to use find_clusters from the GenericNetwork, rather than building adj_mats locally.
Minor tweak to count...now accepts plural and singular element strings
Create a new subclass of list with cleaner printing
- This class is called PrintableList
- It is stored in misc
- props and labels are converted to this class before being returned
- if you use print(pn.props()) you'll get a nice clear printout
Merge branch 'pr/157' into feature/Voronoi

Conflicts:
	OpenPNM/Algorithms/__LinearSolver__.py
	OpenPNM/Network/__GenericNetwork__.py
Made a few changes to LinearSolver so that the Voronoi code will work
- LinearSolver no longer checks for coplanarity unless specifically asked (check_health=True)
- Removed Tom's kludge in the misc file
- Tested the normal run_script with this code and it works fine too, so it's ready for merging.