Update Examples importer

Node-based examples importer. Combined with updating source repos in-place, and this gives a tremendous speed boost:

### Before

    import_examples  3.28s user 2.54s system 13% cpu 42.853 total

### After

    import-examples  4.47s user 6.62s system 106% cpu 10.420 total

Some stuff could probably also be made concurrent in the future for even faster imports.