trema/trema — pull request #201 by userlocalhost2000 (2012-08-28 10:15:11+00:00)
Title: correct invalid conditional statement and add usage

Dear all

I correct the invalid conditional parameter and add usages of each function.

A short optional parameter of 'h' is set in getopt_long() for help. But '?' is set for conditional parameter at each switch-statement after calling getopt_long().
This correction, '?'->'h', is suited to other programs that requires command-line options in Trema.

And for adding usage, you can see usage of each function, like following.

```
~/trema$ objects/phost/cli set_host_addr -h
usage: cli set_host_addr [-v] [-h] [--ip_addr ip-address] [--ip_mask netmask] [--mac_addr mac-address]
2012/08/28 19:03:01.764411 [ ERR] (cli.c:139:main) cannot execute.

~/trema$ objects/phost/cli add_arp_entry -h
usage: cli add_arp_entry [-v] [-h] [--ip_addr ip-address] [--mac_addr mac-address]
2012/08/28 19:03:01.766938 [ ERR] (cli.c:139:main) cannot execute.

~/trema$ objects/phost/cli delete_arp_entry -h
usage: cli delete_arp_entry [-v] [-h] [--ip_addr ip-address]
2012/08/28 19:03:01.769496 [ ERR] (cli.c:139:main) cannot execute.

~/trema$ objects/phost/cli send_packets -h
usage: cli send_packets [-v] [-h] [--ip_src source ip-address] [--ip_dst destination ip-address]
[--tp_src source transport-address] [--tp_dst destination transport-address]
[--n_pkts amount of packet] [--length length of packet]
[--inc_ip_src] [--inc_ip_dst] [--inc_tp_src] [--inc_tp_dst]
[--inc_payload] [--n_pkts amount of packet]
[--duration sending duration]
[--pps packets per second] [--nonblock] [--background]
2012/08/28 19:03:01.772052 [ ERR] (cli.c:139:main) cannot execute.

~/trema$ objects/phost/cli reset_stats -h
usage: cli reset_stats [-v] [-h] [--tx] [--rx]
2012/08/28 19:03:01.774566 [ ERR] (cli.c:139:main) cannot execute.

~/trema$ objects/phost/cli show_stats -h
usage: cli show_stats [-v] [-h] [--tx] [--rx]
2012/08/28 19:03:01.777115 [ ERR] (cli.c:139:main) cannot execute.
```

Thank you.