Use the standard doctype for this motley crew of midnam files.

Use the standard doctype for this motley crew of midnam files.

By "standard" I mean "actually hosted by the MMA at midi.org".  Where the heck
this broken DTD link to sonosphere.org came from is anyone's guess.  Either
midi.org wasn't doing things correctly back in the day, or somebody is insane.
Probably both.

As a hint to the legacy of this data, some of these documents referred to
version 0.7, and some have mac newlines.  Mac newlines!  Remember those?

git-svn-id: svn://localhost/ardour2/branches/3.0@13883 d708f5d6-7413-0410-9779-e7cbd77b26cf