Add user defined cluster processing

[chrisallen80]

It would be good to add functionality for cluster processing of converted 4DSTEM data (ADF, ptychography, CoM, warping etc). My view is that this should be done separately from the conversion as there are numerous user defined parameters which will need to be checked and set prior to processing on all data-sets.

[chrisallen80]

This has now been implemented for ADF, COM and iDPC:
pull request #15

[chrisallen80]

It would be good to have all output from processing within a single HDF5 file with meta-data corresponding to parameters. Perhaps even run the processing based on HDF5 meta-data rather than the current parameters.txt file