ovs-ofctl: Add meter support.

ovs-ofctl: Add meter support.

Adds commands add-meter, mod-meter, del-meter, del-meters, dump-meter,
dump-meters, meter-stats, and meter-features.

Syntax is as follows:

add-meter <br> meter=<n> (kbps|pktps) [burst] [stats] bands= type=(drop|dscp_remark) rate=<n> [burst_size=<n>] [prec_level=<n>] <more bands>

mod-meter <br> meter=<n> (kbps|pktps) [burst] [stats] bands= type=(drop|dscp_remark) rate=<n> [burst_size=<n>] [prec_level=<n>] <more bands>

del-meter <br> meter=(<n>|all)

del-meters <br>

dump-meter <br> meter=(<n>|all)

dump-meters <br>

meter-stats <br> [meter=(<n>|all)]

meter-features <br>

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>