fix url to reflect new way urls are generated for buckets.
Replace filepath with key in callback_url request.
Ignore the add event from other fileupload forms on the same page
Ignore the add event from other fileupload forms on the same page
converting the form helper to use AWS Signature version 4
fix to signing method
Add a new setting called preprend_files that causes new files to be
prepended to the progress_bar_target instead of appended.
Add method to get addtional data.
Merge commit 'refs/pull/162/head' of https://github.com/waynehoover/s3_direct_upload
Merge commit 'refs/pull/170/head' of https://github.com/waynehoover/s3_direct_upload
Merge commit 'refs/pull/174/head' of https://github.com/waynehoover/s3_direct_upload

Conflicts:
	lib/s3_direct_upload/form_helper.rb
Merge commit 'refs/pull/176/head' of https://github.com/waynehoover/s3_direct_upload
Merge commit 'refs/pull/165/head' of https://github.com/waynehoover/s3_direct_upload
Updated readme