There's a case when you really don't want to make a thumbnail of only the first frame, such as making thumbnail for GIF image. This patch will check that the source and output format is an animated format, and not calling `[0]` on it.

Closes #454

Change S3 storage behavior to get the content_type for each upload, rather than only the original file. This prevents a still frame from a video or a conversion of a file from being served with the original mimetype.

Closes #38, #129

`convert` will pick this up automatically. :)

This addresses an issue where Paperclip can indefinitely block execution
of an application by telling ImageMagick to "identify -format %wx%h [0]"
which will then wait for input from STDIN forever.

Conflicts:

	lib/paperclip/storage/s3.rb
	test/storage_test.rb

For compatibility with Rails > 3.0.0.
(cherry picked from commit 2e6d3370553ef68aeb0deb2b08de3871616139a4)

CommandLine uses Paperclip.options[:swallow_stderr] as a default if no :swallow_stderr option is specified.
(cherry picked from commit 753b8b9fc2cb24c9006fe2e6f48d4fe57519eb7a)

This method prevents excessive calls to the S3 API, creating a bucket
only if the store method fails with a NoSuchBucket error instead of
asking for the bucket before each request.

In my opinion, a permission error should not result in the entire
reprocessing job being terminated. Especially for large amounts of
files, it's to be expected one or two have various permission issues.

Instead of exiting, now simply print a warning to stderr.