D-Link hedwig.cgi - Cookie bof - return to system

This is the second exploit from the advisory by Roberto Paleari (http://www.exploit-db.com/exploits/27283/). As in the module https://github.com/rapid7/metasploit-framework/pull/3385 I have created a ROP to system and this starts the telnetd.

![dlink_hedwig_cgi_bof](https://cloud.githubusercontent.com/assets/497520/3132822/8bd5fca2-e813-11e3-8fd3-a081bf87f8b2.png)

This vulnerability is not only in the DIR-645. It is also in the firmware of the DIR300 and DIR600. I think there could be other devices out there that are also vulnerable.
Okey so, what you guys think about using by default ";" and just allowing the exploit to change the concatenation character by itself if needed? It would make the CmdStager modification easy, the CmdStager would work as is by default, but modules like the one in this pull request can provide their own concatenation character at its own risk.