- particle set weight operator (Shift + K) and from the menu.
- mirror vertex groups operator can also flip weight group names.
a number of utility functions for weight groups added
int *get_defgroup_flip_map(struct Object *ob);
void flip_vertexgroup_name (char *name_r, const char *name, int strip_number); // moved from modifier.c
void copy_defvert (struct MDeformVert *dvert_r, const struct MDeformVert *dvert);
void flip_defvert (struct MDeformVert *dvert, int *flip_map);