Fix texture and object console paths

- Be sure to delete all prefs.cs files following this change.
- Changes the console types of the missing, unavailable and warning
texture paths.  The old type was causing string corruption when saving
preferences.
- Changes the console type of the TSShapeConstructor collision shapes.
The old type was causing string corruption when saving preferences.
- Changed missing texture reference in ProcessedMaterial from String to
const char*.