Improved Debugpy path finder

Improved Headless Debugging

Added a parameter to command to allow auto starting the server.

This allows easily debugging blender when running headlessly.

Closes #26

Fixes potential trailing space in path problems.

- Closes #17

Updated for Blender 2.80

Changed default port + Added ability to select Port

- Closes #10
- Minor changes/improvements.

Support for ptvsd version 4 + Other Improvements

- Fixes #8
- Improved python path searching code.
- Added documentation regarding usage with virtual environments.
- Added link to single file scripts workaround issue. Closes #4

Added License

- Fixed #2

Added PTVSD Version Warning

- Added documentation about ptvsd version and link to the related visual studio docs.