[PATCH 48361] Add global server option for specifying desired DSCP/QoS markings

[Philip A. Prindeville]

This patch leverages 42848 to add the QoSMarking configuration directive to the 
server.

The markings are specified as "cs0..cs7", "af11..af43", or "ef" (as per RFC's 
2474 and 2597/2598).

Please review and comment.