CADET feature support

Support some new CADET features currently in testing without changing the API

Locking

This version now optionally allows the files to be locked during reading or writing using the python filelock library. This is important when reading and writing hdf5 files that could potentially be read or written to by parallel processes.

Loading subpaths

This release fixes a problem with loading subpaths

load path change

Don't raise a KeyError when a path specified for loading when that path can't be found. Paths are meant to restrict what can be loaded not create errors if not found.

JSON reading and write

JSON reading and writing have been added

Load changes

Recursively load handles paths better and will load the path plus all children.

PyPi release

CADET python has been used for over a year now to interface with CADET in production systems. It still needs more documentation and examples. This interface works with CADET through a file based interface using HDF5 and as a result works with any version of CADET.