Validate URLs for querying Bit.ly API in a single subroutine; allow FTP links because they can also be shortened
Add new FIXME (some HTTP redirects don't seem to work with LWP::UserAgent)
Don't exit of links are invalid (e.g. link such as "urn://sopa.google.search/SOPA" shouldn't kill the whole script)
Remove FIXME because the URLs that are failing are certain NYTimes URLs who get into a redirect loop