Automatically disable ssl certificate hostname checking against AWS S3

http://docs.aws.amazon.com/AmazonS3/latest/dev/VirtualHosting.html

  "When using virtual hosted–style buckets with SSL, the SSL wild card
   certificate only matches buckets that do not contain periods. To work
   around this, use HTTP or write your own certificate verification
   logic."

Therefore, when we detect we are sending a request to
*.s3.amazonaws.com and are using SSL, we must disable hostname
checking. This seems to only impact python 2.7.9 and newer, as that's
where the new SSL context and checking exist.