[BlendLuxCore] New Development Feature: Environment Variables

[CodeHD]

For simplification of the addon development process, a new mechanism has been added to allow running the addon from a local git repository.
Two environment variables are now checked by the main "__init__.py" script:

• BLC_WHEEL_PATH: If set as the path to a local pyluxcore wheel, this version will be used instead of downloading via pip
• BLC_DEV_PATH: If set as the path where the local BlendLuxCore/ folder is located, the code from this path will be executed.

The first is necessary as part of the new use of pyluxcore wheels, to be able to use local development builds that are not on PyPi.

The second allows to work with a single git-repository folder across multiple versions of Blender, which will become relevant when maintaining several LTS versions of Blender. Switching between branches should not cause issues unless "__init__.py" itself is modified.

As an additional suggestion: Attached here are two example batch/bash scripts for Windows and Linux that set the variables and launch blender. Placing these scripts on yur local PATH - with paths adapted to your system, and renaming the script to something of your choice - allows to quickly start Blender in development mode.