Adjust part size as needed in create_archive_from_file

Fixes #1478, original patch suggested by @dminkovsky.
If we have a large enough file such that the default part size
is not sufficient to stay within the maximum number of parts
allowed by glacier, we automatically adjust the part size
to the minimum required.  We were previously calculating this
value but not actually doing anything with it.
Add release note item for bug fix
Merge branch 'glacier-partsize-fix' into develop

Closes #1478

* glacier-partsize-fix:
  Add release note item for bug fix
  Adjust part size as needed in create_archive_from_file
Fixed regex that failed on S3 buckets with uppercase letters.
Merge pull request #1503 from reinhillmann/develop

Fixed regex that failed on S3 buckets with uppercase letters.
A few PEP8 fixes and added some missing files to the EC2 ref docs index.
Merge branch 'develop' of github.com:boto/boto into develop