New version of Proxy access control list documentation

Dear List,

please review the following wiki section:

http://wiki.ipfire.org/en/configuration/network/proxy/wui_conf/access

which I heavily modified from the previous text. The part I modified is in between:

begin section to be reviewed

end section to be reviewed

I particular, please check carefully the part before the image of the web interface and the paragraphs titled:

Disable internal proxy access to Green from other subnets

and

Disable internal proxy access to other subnets from the Blue IP space (except the IPFire machine itself):

Let me state that the author(s) of this text did an amazing job and allowed me to understand how to configure the proxy the way I wanted. My modifications are intended only to try to make it more clear to a beginner and to correct an error in the text, as discussed previously in other mails on this list.

I welcome any criticism. I will wait until you give me permission to remove the "under review" notice.

Thank you.

Cheers.