Integrate NatureWatchNZ bulk uploader

NatureWatchNZ wrote their own CSV upload tool that could handle many more rows and process the file in the background. That was better than ours, so I replaced ours with theirs. I also included their support for multiple coordinate systems, but it can only be specified in the `config.yml` file. I cherry picked off of their repo, so unfortunately the full commit history was lost, but you can see it all at https://github.com/nzbrn/naturewatch/pull/20.

@calonso-conabio, there a number of things I haven't translated here, so you might want to check out the diff of `en.yml`