Checkin of the source code for midi2 kit milestone 1.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2335 a95241bf-73f2-0310-859d-f6bbb57e9c96

some midi2 headers


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1613 a95241bf-73f2-0310-859d-f6bbb57e9c96