- use list to show bmap encoding settings, instead of user input raw string. it will give a more obvisous interface.
* add bmap encoding setting properties in ptrprop_resolver.
* update ptrprop_resolver for more clear usage.
- following features has not been implemented yet.
* default value for bmap encoding list.
* the bridge function in ioport_shared module (filter empty item in result)
* validate encoding list result when importing and exporting virtools file.
- fix all `def poll(self)` to `def poll(cls)` to let it fit class method name convention.
- fix wrong progress counter when importing virtools file.
- add light support when importing virtools file.
- add corresponding conflict strategy and resolver for light.
- finish uv section of doc.
- fix issue about the wrong calc of coordinate system axis vector in flatten uv (change it from left hand to right hand).
- fix rail uv display text.
- sync PyBMap work. use different library name in different OS.
- add BMap encoding default value according to different OS (Windows and non-Windows) because non-Windows OS, we use libiconv as encoding converter.
- move all pointer properties to a single module and give corresponding visitor.
- add shared importer exporter parameters module thus bmfile import/export also can ref it.
