Revert "add requirement for importlib"

This reverts commit 13b8f0e6a7746ae656046ea6fc1df3da23d93c22.

Revert "* updated list of links computed from links_data (rather than grabbing arxiv ids from ids_data)"

This reverts commit 7546f301437e830607b51866ae3452a274d9f0ac.

Revert "Fixed keyword display, eliminated empty affiliations"

This reverts commit 5a6b450d3ced9b3306e862ab5a8aef516bce4d88.

Revert "Fixed keyword/schema mapping in normalized solr document, eliminated empty affiliations and emails"

This reverts commit a9d4f77d1b17ecf6f09d60a1b47360c8a48c051c.