- add edit mode switch before bm export to prevent potential error
- let the default value of ZBuffer in Virtools Material become True
- fix the issue that duplicated elements adder do not understand enable option.
- add support of 4 alpha fields intorduced in BM spec recently.
- optimize material creation functions argv passing strategy.
- change related func calls of (2).
- optimize material parameter pick code to reduce useless check.
- split blender material creation function.
- allow user to apply virtools material to blender nodes in operator.
- add quick group picker in add virtools group operator.
