Custom Min & Max

[andrewcallahan]

I need a way of specifying a custom min/max on the graph's y-axis. My primary use case is percentage graphs that need to always be 0-100, which doesn't work with the current dynamically generated y-axis that varies depending on the data.

This code isn't at all production quality but it gets the job done for my narrow use case. Before I proceed I want to gauge the likelihood this feature would be accepted/merged and what kind of interest there would be in helping to clean it up, refactor, fix broken tests, add new tests etc.