explicit proxy setting for curl-loader-0.47

[<Fra...@ma...>]

Dear Curl-Loader maintainers,

I needed a way to switch off or explicitly set the curl proxy string for 
curl-loader, without touching the environment or .curlrc.
I couldn't find a hint in the docs or FAQ, so I implemented the "-x" 
option from curl in a quick and dirty way to curl-loader.
Now I am able to do:

./curl-loader -x "" -f ssl-loadtest

Where '-x ""' unsets the proxy. It might be of interest for others and I 
believe it is worth implementing, so I attach the diffs. 

I couldn't find quick enough the size for the proxy string, I simply set 
it to char[255] but it might be worth to look up or use the definition 
from the curl sources.
I am also not sure if I placed the curl_easy_setopt (handle, 
CURLOPT_PROXY, config_proxy); call optimal in loader.c, But it works fine 
for me at the moment.

Cheers,
Frank

fm@mlp09325:~/dev/curl-loader-0.47> diff conf.h.orig conf.h
114a115,120
>    Name of the configuration proxy.
> */
> extern char config_proxy[254 + 1];
>
>
> /*


fm@mlp09325:~/dev/curl-loader-0.47> diff conf.c.orig conf.c
74a75,77
> /* Name of the configuration file */
> char config_proxy[254 + 1];
>
87c90
<     while ((rget_opt = getopt (argc, argv, "c:dehf:i:l:m:op:rst:vuw")) 
!= EOF)
---
>     while ((rget_opt = getopt (argc, argv, "c:dehf:i:l:m:op:rst:vuwx:")) 
!= EOF)
187a191,200
>         case 'x': /* set/unset proxy */
>           if (optarg)
>             strcpy(config_proxy, optarg);
>           else
>             {
>               fprintf (stderr, "%s error: -x option should be followed 
by a proxy IP or name.\n", __func__);
>               return -1;
>             }
>           break;
>
223a237
>   fprintf (stderr, " -x[set|unset proxy]\n");


fm@mlp09325:~/dev/curl-loader-0.47> diff loader.c loader.c.orig
483,485d482
<
<   /* set|unset the curl proxy */
<   curl_easy_setopt (handle, CURLOPT_PROXY, config_proxy);