documentation marathon :-)

[Emmanuelle Gouillart]

	Hello,

as I was browsing through the scikit, I started to make a list of
functions for which we don't have examples (neither in their docstring,
nor an example script for the documentation/example gallery). I copy it
here, since it seems a priority to me that we have more examples in the
documentation. I was thinking of writing an example of edge detection wih
canny and sobel, and completing their docstrings while I'm at this. Any
other volunteer to make this list shrink :-)?

Cheers,
Emmanuelle

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feature: hog 

filter: median_filter, canny, sobel, prewitt, wiener

graph: shortest_path, MCP

morphology: 
* structuring elements in selem.py don't have examples in docstrings. 
* In grey.py, Tony added recently examples in all the
docstrings -- it'd be great to have also a few examples for the gallery
* label doesn't have examples

transform: probabilistic_hough, homography, integral_image, integrate
radon and iradon do not have examples in docstrings (but they do have a nice 
example in the gallery)