Update docs badge in README

Update the URL of the docs badge to include it from inch-ci.org instead of inch-pages.github.io (the former being the successor of the Inch Pages project).
Describe workaround for false spoofing errors

As described in issue #1470, Paperclip can sometimes raise undesired spoofing errors when working with custom extensions. This adds an example workaround in the README using the public API of the mime-types library that will resolve this issue in a way compatible with Paperclip.
Add a japanese translation file
Add pt-BR locale
Update README to reflect most recent gem version
Uses a faster implementation for ensure_required_validations!
Use stream downloads for S3 objects as suggested by aws-sdk
documentation.

They recommend sending a block to the #read method to avoid loading
large objects into memory. See:
http://docs.aws.amazon.com/AWSRubySDK/latest/AWS/S3/S3Object.html
Remove duplicated attr_reader.

Remove duplicated attribute :whiny.
Merge pull request #1616 from carpodaster/patch-1

Update README to reflect most recent gem version
Merge pull request #1615 from guilhermefelipecgs/master

Add pt-BR locale
Merge pull request #1610 from willnet/japanese-translation

Add a japanese translation file
Merge pull request #1602 from norman/patch-1

Describe workaround for false spoofing errors
addressed issue #1324 for URL escaping of (, ), [, and ] characters.
Merge pull request #1559 from rrrene/patch-3

Update docs badge in README
Fix content type indeterminism on Travis
Honor fog_credentials[:scheme] option