bugfix: 802.11n devices did not use 802.11n datarates

This adds support for 802.11n data rates on the mesh.

This should improve dataspeeds across the board

MIMO devices like Rocket and NanoStation should be able to use dual chains which allows diverse data transmission on each chain increasing throughput

MCS data rates in theory should cut through noise better than legacy modulation and have higher speeds on each step which should allow overall higher datarate between nodes.

files/etc/config.mesh/wireless

@@ -4,6 +4,7 @@ config wifi-device  radio0
         option chanbw   <wifi_chanbw>
         option distance <wifi_distance>
         option country <wifi_country>
+	option htmode	HT20
 include /etc/aredn_include/radio0path
 
 config wifi-iface