Blender Git Loki

Text3d: store number of characters and utf8 length separately

EditFont's use of Curve.len was very confusing, in editmode it
represented the number of characters, in object mode the number of
bytes. add Curve.len_wchar and keep track of both.

Also don't convert the editmode text into utf8 on every keystroke.
Now this is done on exiting editmode or save - to match most other
object types.

This also fixes curves 'body_format' being reported with an invalid size.