Fix attribute storing error

Replace BGL with GPU module for 4.0

Completely removes BGL module and replaces with the new GPU module so it works with 4.0

Merge branch 'v1.2' without Gradient Tool/Sharpen

Adds filter mask/weights changes
Adds conversion of normals to vertex colors and vice versa
Adds panel location changing from N panel to Header option
Switch mac drawing name to alt drawing to avoid confusion of only working on mac systems
Rename Self to Modal for code clarity

Update __init__.py

Fix confirm and cancel changes buttons error

Revert "Merge pull request #11 from BlenderNPR/v1.1"

This reverts commit 5315095, reversing
changes made to d6faf02.