Finished appleseed / blenderseed build script, fully working with ble… …nder v2.82a & v2.83. Dependencies are built using Blender's dependency build pipeline and are therefore guaranteed to be fully compatible.

Overhauled patch system & updated build script for 2.83 release 

Added version selection (currently 2.82a, 2.83) & hardened bpy build. 

Added version selection (currently 2.82a, 2.83) & hardened bpy build. 

v1.2, reverted Blender version 2.83 -> 2.82a until stable, fixed blen… …derseed compilation not working correctly.

v1.1, switched devtoolset 7 -> 6, since this is the version that is u… …sed for official builds.