Merge develop and master branches with proper git merge

Add kw args to Path.stat

Add LTREditor to toolset

Offload `Scene` texture loading to another thread.

Add missing erf_relpath param when extracting a single file from ERFEditor

Various refactors to Module handlers and QOpenGLWidget lifespans.

Slight repo restructure

Fix DLG camera angle selection

Fully open source the compile process

#95 (continuation of #94)