[#128,backend/elasticsearch][s]: standardize on url field on dataset to hold url for ES backend.
[#128,backend/elasticsearch][s]: standardize on url field on dataset to hold url for ES backend.

* also ensure reasonable docs for all methods

modulexcite/recline,okfn/recline,modulexcite/recline,gotjoshua/recline,GerHobbelt/recline,GerHobbelt/recline,NuCivic/recline.js,rjsteinert/recline,NuCivic/recline.js,acouch/recline,boban-dj/recline,okfn/recline,huangciyin/reclinejs-requirejs,NuCivic/recline.js,maxogden/recline,modulexcite/recline,beni55/recline,acouch/recline,beni55/recline,boban-dj/recline,maxogden/recline,gotjoshua/recline,beni55/recline,okfn/recline,GerHobbelt/recline,acouch/recline,boban-dj/recline,rjsteinert/recline,rjsteinert/recline,huangciyin/reclinejs-requirejs,gotjoshua/recline