- add struct assigner and iterator but still has bugs (struct padding issue)
- add function bindings for BM3dObject and BMGroup.
- add basic ctor and dtor for BMMeshTrans.
- fix weird C sharp behavior about calling FreeNativeData without calling ManagedToNative, which cause segment fault.
- disable unhandled exception handler in debug mode for BMap.
- change all associated code involving these issues.
