0.4.11 Documentation Omnibus

I'm creating this issue to track things that need improved documentation for the 0.4.11 release. As you come across things, please comment and I'll add them to the list.
## Things To Document For 0.4.11
### Add new documentation
- `chart.title`
- `chart.subchart.axis.x.show`
- Overridable globals via `c3.chart.internal.fn.additionalConfig`
### Update existing documentation
- The entire "CLASS" section. Might take a bunch of screenshots of charts, highlighting elements with a specific class. This is long overdue and would save so many support requests...
- Using the JSON API with timestamps as per [#805](https://github.com/masayuki0812/c3/issues/805#issuecomment-125182488).
- [data.order](http://c3js.org/reference.html#data-order) is confusing if you don't realise it only applies to stacked data or pie/donut pieces. A bit more signposting couldn't hurt.
- [data.xSort](http://c3js.org/reference.html#data-order) — SRSLY, what does it do?