Adds jsonLoad option which allows for function or object json

Moved the getData method from inside jsonPath to generalized, so it can be used in both circumstances.

Defines a new option `jsonLoad` which defaults to `false` and accepts either an `object` or `function` (without any type conversion - mirroring `jsonPath`)

For examples on usage check #113 #114

https://github.com/OwlFonk/OwlCarousel/issues/113
https://github.com/OwlFonk/OwlCarousel/issues/114

If pull is approved, can send another with the mirror'd doc pages I created (based on demos/json.html)