Fix for legend.remove() bug with matplotlib < 1.4
The linked commit hacks around bug #37 (closed) by catching the NotImplementedError
raised by mpl < 1.4 and simply hiding the legend instead. I've tested generating the examples for the documentation, and things look fine.
@areeda, without thorough testing, can you tell me whether this is good enough. I'd rather not place a hard requirement on matplotlib >= 1.4 just yet.
This PR fixes #37 (closed).