Revert "Simplified code and updated formating"

This won't work if there's an `afterOpen` specified, as the extend will overwrite the one in the config.

This reverts commit f88f2c675cad53b8ba3a9a5880de44e2d768caba.
Have consistent calling convention and argument naming
Add contentFilters.
Improve the heuristics.
Break getContent in two
$.featherlight is now always a way to open a lightbox, never a way to bind events
Remove autostart option.