Fixes and improvements

Relies on https://github.com/phpDocumentor/GraphViz/pull/10 being merged first for path to have any effect. Then it works on Windows - flawlessly :)
But also without the path being manually adjustable, this already works quite well now in 2.x.

Also
- Added Configure config approach
- Defaults to TMP as storing folder
- Excluded AppModels and some known Debugging/Setup plugins
- Folder simplified to "GraphViz"
- Corrected readme
- CS fixes and minor code improvements.