Fix#2435, this very slim patch (including its relevant documentation addition) adds a small option to line chart datasets (spanGaps) that allows users trying to graph sparse datasets to have lines between null entries drawn, rather than omitted.
Usage: If a label is an `array` as opposed to a `string` i.e. `[["June","2015"], "July"]` then each element is treated as a seperate line. The appropriate calculations are made to determine the correct height and width, and rotation is still supported.
view samples/line-multiline-labels.html to see it working.
On branch multiline_labels
Changes to be committed:
modified: docs/03-Line-Chart.md
new file: samples/line-multiline-labels.html
modified: src/core/core.helpers.js
modified: src/core/core.scale.js
