Remove / fix VCS interact warning

[aashish24]

Adding VCS element: 3d_scalar xyt
/Users/williams13/work/uvcdats/build_uvcdat/install/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcs/Canvas.py:3729: UserWarning: VCS Behaviour changed, in order to interact with window, start the interaction mode with:
x.interact()
warnings.warn("VCS Behaviour changed, in order to interact with window, start the interaction mode with:\n x.interact()")

[doutriaux1]

No this warning is on purpose. As the warning clearly states the behaviour changed. People would not know how to interact with a window otherwise. We can setup a flag to turn off this warning in the .uvcdat directory if you want. But we need to keep this warning for at least 2.0 and probably 2.1. Moving to 2.1, not closing now.

[durack1]

It also seems like at least in builds from late last month, there are some print statements which probably need to be removed:

zg-500   inmcm4    u'40.90'  WITH global
/usr/local/uvcdat/2014-08-22/lib/python2.7/site-packages/vcs/Canvas.py:5361: UserWarning: need to implement code to redraw vcs after colormap change
  warnings.warn("need to implement code to redraw vcs after colormap change")
here we go
Traceback (most recent call last):
  File "portrait_test.july23.py", line 96, in <module>
    P.plot(out1_rel,bg=0)

[doutriaux1]

duplicate #651