Stoner

Allow PCAR script to take a filename from its config file. Minor bug fixes.

This is the first release of the 0.9.x cycle. Highlights include:

* Refactoring of the package into a more granual core, plot, formats, folders packages with submodules
* Overhaul of the documentation and user guide
* Dropping support for the older Stoner.Image.stack.ImageStack class
* Droppping support for matplotlib<2.0
* Support for Python 3.7
* Unit tests now > 80% coverage across the package.

2nd release candidate for 0.9.0 release

First release candidate of the 0.9 branch.

First alpha release for version 0.9.0 branch.