DSCP were not matched correctly, also DSCP VA was missing

DSCP values specified in a firewall rule matched not only the specified value, but also other values. See https://forum.pfsense.org/index.php/topic,67824.0.html

Also, the VA code point was missing, so i added it while I was on it.
Merge pull request #149 from Klaws--/patch-4

DSCP were not matched correctly, also DSCP VA was missing