catch http errors lower down and retry a couple times

[NovemLinguae]

http errors are by far the most common errors in the error log for GANReviewTool. these could be dealt with more gracefully by catching them down low and retrying 2-5 times before giving up completely.

These errors are a big deal. They cause partial promotions, which are a pain to fix. And in one recent case, they caused a new user of the script to think it was a broken script and immediately uninstall it.