* Configuration parameters are being used for testing the EdReference, but
  configuration changes are not reflected in the interface. Fix this.

* Texture Attributes can't be accessed with getAttribute, must use
  getTextureAttribute. But for this we must implement before the following
  two points:

* Implement EdReference to allow having attributes that are references to
  other editables, maybe alowing to reference some different classes (all
  child of the same superclass, to have sense).

* Implement EdReferenceList, a list version of the previous concept. This
  would allow to edit in a reasonable way the StateSet with it's list of
  StateAttributes which can be (and *must*) of different classes. This list
  should allow adding and removing elements, not like the static version
  that we already have.

* GTK-only version to port it to windows

* Implement support for more state attributes

* Draw Axis on the screen for each transform operation to allow doing it in
  all or only one axis

* Fix a bug with make_current when more than one editors open

* Implement a model library both global (in /usr/lib/osgedit) and local (in
  ~/.osgedit) so that user can have their models organized.
