ReactS3FineUploader used to check the current url’s query params to
determine which method it should use to upload, but this decision means
the component is tightly coupled with react-router and history.js. A
major pain point is having to propagate the location prop all the way
down to this component even when it’s not necessary.
Now, ReactS3FineUploader’s parent elements can either parse the current
query params themselves or, if they have a location from react-router,
simply use the location.
Added a few utils to help parse url params.
