Added more error checking and human-readable replies to derpibooru script.
Added extra error checking to dictionary script plus human-readable error on failed connection.
Replaced tab whitespace with spaces.
Merge pull request #33 from ShockkPony/master

scripts/derpibooru, scripts/dictionary: error handling

This seems somewhat temporary, but is needed. Eventually we will want to use the errback in modules/http_client, but a more graceful solution is needed there.