Add a "sin()" function to charts
Depends on D20443. Ref T13279. This is probably not terribly useful on its own, but is mostly a function which takes another function as an argument, and a step toward more useful functions like arithmetic and drawing a picture of an owl.
The only structural change here is that functions now read data parameters (domain, sample limit) using a more tailored "ChartDataQuery" instead of reading the actual axis. Mostly, I want a more cohesive representation of query state that can be easily passed to sub-functions, as here.
Reviewed By: amckinley
Maniphest Tasks: T13279
Differential Revision: https://secure.phabricator.com/D20444