Add dataJson option in geographyConfig
Add dataJson option in geographyConfig

This PR allows the use `dataJson` in `geographyConfig` to specify a custom topojson file as a string, instead of having to use `dataUrl` and link to an external file. This is especially useful in generating standalone html files with no dependencies.
tim777z/datamaps,BeatrootApp/datamaps,travisbenton/datamaps,markmarkoh/datamaps,smkand/datamaps,smkand/datamaps,workgena/datamaps,jsmapr1/datamaps,thebenedict/datamaps,jsmapr1/datamaps,francescoagati/datamaps,travisbenton/datamaps,dmachat/datamaps,enricoberti/datamaps,workgena/datamaps,thebenedict/datamaps,arshad/datamaps,francescoagati/datamaps,markmarkoh/datamaps,tim777z/datamaps,smirecki/datamaps,BeatrootApp/datamaps,arshad/datamaps,halloweenkeyboards/datamaps,BenHeubl/datamaps,justmarkup/datamaps,justmarkup/datamaps,enricoberti/datamaps,BenHeubl/datamaps,solova/datamaps,solova/datamaps,dmachat/datamaps,smirecki/datamaps,halloweenkeyboards/datamaps