Allow TC_TYPE=CBQ setting for backwards compatibility, although
it is ignored. Add documentation for TC_TYPE=HFSC.

--- conf/zone.dmz.orig	2012-08-11 11:39:38.768938567 +0000
+++ conf/zone.dmz	2012-08-11 11:47:25.351855722 +0000
@@ -144,12 +144,16 @@
 ## Usage:
 ## TC_ENABLE=0|1
 ## TC_TYPE=HTB|HFSC
+## TC_VOIP=0|1
 ## TC_UPLINK=<kbits>
 ## TC_DOWNLINK=<kbits>
 ## The type specifies which shaper is to be used. The HFSC shaper has more
 ##   features than the HTP shaper, but may not be available on all systems.
 ##   See http://luxik.cdi.cz/~devik/qos/htb/ for info about HTB, and
 ##   http://www.cs.cmu.edu/~hzhang/HFSC/ for info about HFSC.
+## TC_VOIP is only implemented for HFSC type shaper. It reserves a minimum
+##   bandwidth for voip traffic, and creates a special high priority class
+##   for voip related traffic.
 ## The speeds should be below the actual speed of the link. 
 TC_ENABLE=0
 TC_TYPE=HTB
--- conf/zone.ext.orig	2012-08-11 11:39:38.768938567 +0000
+++ conf/zone.ext	2012-08-11 11:47:43.440860308 +0000
@@ -136,12 +136,16 @@
 ## Usage:
 ## TC_ENABLE=0|1
 ## TC_TYPE=HTB|HFSC
+## TC_VOIP=0|1
 ## TC_UPLINK=<kbits>
 ## TC_DOWNLINK=<kbits>
 ## The type specifies which shaper is to be used. The HFSC shaper has more
 ##   features than the HTP shaper, but may not be available on all systems.
 ##   See http://luxik.cdi.cz/~devik/qos/htb/ for info about HTB, and
 ##   http://www.cs.cmu.edu/~hzhang/HFSC/ for info about HFSC.
+## TC_VOIP is only implemented for HFSC type shaper. It reserves a minimum
+##   bandwidth for voip traffic, and creates a special high priority class
+##   for voip related traffic.
 ## The speeds should be below the actual speed of the link. 
 TC_ENABLE=0
 TC_TYPE=HTB
--- conf/zone.int.orig	2012-08-11 11:39:38.769938408 +0000
+++ conf/zone.int	2012-08-11 11:47:56.441855445 +0000
@@ -132,12 +132,16 @@
 ## Usage:
 ## TC_ENABLE=0|1
 ## TC_TYPE=HTB|HFSC
+## TC_VOIP=0|1
 ## TC_UPLINK=<kbits>
 ## TC_DOWNLINK=<kbits>
 ## The type specifies which shaper is to be used. The HFSC shaper has more
 ##   features than the HTP shaper, but may not be available on all systems.
 ##   See http://luxik.cdi.cz/~devik/qos/htb/ for info about HTB, and
 ##   http://www.cs.cmu.edu/~hzhang/HFSC/ for info about HFSC.
+## TC_VOIP is only implemented for HFSC type shaper. It reserves a minimum
+##   bandwidth for voip traffic, and creates a special high priority class
+##   for voip related traffic.
 ## The speeds should be below the actual speed of the link. 
 TC_ENABLE=0
 TC_TYPE=HTB