s3 url doc improvements
This should fix the problem on animated file detection. Fixes #851
This should fix an error when the user has turn on AWS logging while and upload a file with non-English filename, as `aws-sdk` logger is not encoding aware. The problem was that the string returned from another logger methods is in `US-ASCII`, while the string returned from Paperclip would be in `UTF-8`. When the logger calls `#join` on those strings, Ruby would raise an exception. This solution is not the best, as it involves a monkey-patching, but should make sure that the upload goes through without any hiccup. For the long run, I'm going to send a patch to `aws-sdk` and also make Paperclip require at least `aws-sdk > 1.4.1`
We've changed some of the setting and some of the S3 tests got ignored. This should make sure that the tests are really passing, after the changes to IO Adapter.
This will prevent a pitfall as sometime the style's name can be a string.