remove warnings_as_errors flag as it stops builds on R16B03
Merge branch 'jc/warnings-not-errors'
Prevent sending duplicate content-type headers

If the user specifies a content-type header that the file should be
served with from S3 a duplicate header containing the default value will
also be set by ibrowse, resulting in a signature failure and the S3
request being refused.
Merge branch 'master' into hex-fixes