backport from trunk (r570206)

Sync with IANA registry.

Update common x-types that have been registered or will never
be registered for compatibility reasons.  Yeah, those x-Idiots.

The extensions recently assigned to application/vnd.apple.installer+xml
(dist distz pkg mpkg) are too numerous and too generic.  We should
always assume that vendors are too lazy to check for conflicts
(we choose .mpkg only, since that is the common one).

The extension recently assigned to ecmascript (.es)
interferes with languages (espanol), so replace with .ecma.
PR: 35550

Assign the .chm extension to the newly registered type based on
the theory that Microsoft will use it eventually.
PR: 37798

Add application/xspf+xml xspf since they are trying to do it right.
PR: 39317

Add svgz to list of image/svg+xml extensions as per W3C.
PR: 31483



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@570217 13f79535-47bb-0310-9956-ffa450edef68