Reorganized into separate directories

Things were getting crowded.
I considered moving over the example images, but I thought better of it
because users are likely to run the scripts themselves.  The Python
versions produce image files with the same names as the examples, and
I don't want to overwrite the example images.  An alternate approach
would be to move everything over and change the output filenames for
the Python scripts.  This is probably the thing to do.

Another advantage of this approach is that it allows me to write
commentary for each of the scripts by putting a readme in the
separate directories.
Temporarily revert change to separate folders
Revert "Temporarily revert separate folders"

This reverts commit 6fd54d066a036f5f2af2587b66ff738a9ddf6757.
Now it's in its own branch
Work around bug

I'm probably just using a bad version of matplotlib, but I hit a bug
in axes3d.  This change checks for the buggy behavior and retries
with a workaround based on my reading of the buggy source code.
Fixed relative path

So that scripts can find the example data
Links to subfolders
Added links to subdirectories
Correct branch names in absolute path

Absolute path is needed for the website, unfortunately
Fix paths
Fixed paths again
Fixing paths again
Fix absolute paths for real, I think
Stacked area

Added a stacked area plot, bringing Python examples to parity
with Matlab.
readme for stacked area
Added to the note about series versus array
Changed paths because of merge with master