Changes to the way props and labels work.
- they used to return a dict named 'pore' or 'throat'
- now they return a list containing both 'pore' and 'throat'
- you can send 'pore' or 'throat' as an argument to get only one type
Improved the health checks
- There is now only one, data_health
- It prints pretty list of the status but also returns True for healthy and False for ill
Added Siblings mode to the clone method.  This means that a batch of pores can be cloned and they will retain the throat connections to each other.
Trying to get VTP working, still broken