Demomaster application framework with wxpython navigator

now that works (both oceandemo and oceandemo2) and I say it was worth the time spent 'cos is really awesome! very nice the addition of the nature-grass demo either.

just to not make you rest too much I gotta another bug to sendya, related to all the demos that concern the shadowcaster2 - here’s the traceback:

Traceback (most recent call last):
  File "demomaster.py", line 373, in <module>
    run()
  File "linuxroot/usr/share/panda3d/direct/src/showbase/ShowBase.py", line 2266, in run
  File "linuxroot/usr/share/panda3d/direct/src/task/Task.py", line 965, in run
  File "linuxroot/usr/share/panda3d/direct/src/task/Task.py", line 903, in step
  File "linuxroot/usr/share/panda3d/direct/src/task/Task.py", line 802, in __stepThroughList
  File "linuxroot/usr/share/panda3d/direct/src/task/Task.py", line 721, in __executeTask
  File "demomaster.py", line 197, in InitDemoLater
    demo.InitScene()
  File "./demo_ode/ode1.py", line 57, in InitScene
    self.LoadLights()
  File "./demo_ode/ode4.py", line 73, in LoadLights
    self.changeLightPos(None)
  File "./demo_ode/ode4.py", line 80, in changeLightPos
    self.sMgr.castercam.setPos(v[0],v[1],v[2])
AttributeError: ShadowManager instance has no attribute 'castercam'