Description of problem:
A feature in gnuradio (The WG GUI Waterfall Sink in gnuradio-companion) does not work without PyOpenGL. PyOpenGL is not depended on by gnuradio. It seems that gnuradio should depend on PyOpenGL.

Version-Release number of selected component (if applicable):
3.7.2.1-1.fc20

How reproducible:
I only tested it on my machine.

Steps to Reproduce:
1. Install the gnuradio package
2. Open gnuradio-companion
3. Create a WX GUI Waterfall Sink
4. Create a noise source or other non-constant signal source.
5. Connect the blocks
6. Execute

Actual results:
The waterfall plot is solid blue and there are no options on the right side of the plot.

Expected results:
The plot reflects the output of the source and there are options on the right side of the graph.

Additional info:
I installed PyOpenGL and got the expected results. I uninstalled PyOpenGL and it stopped working. I installed PyOpenGL again and got the expected results.