Axis values and titles

[Minnd]

Hi there! First of all congrats for an awesome library! It's far the most clean, clear and nice graph library out there :D!

Nevertheless, I still have some problems. Is there a way to add the axis with a range of values and a mini title explaining what the values are? I really need this feature but I don't want to end using other libraries.

Cheers!

[Daniel Nadeau]

Up to the implementer. However, if you submit a pull request with the code, I'd be happy to take a look :)