Add WebTester 5.x Command Execution exploit module
Fix check method and set a big space available for payload
Land #2534, @bcoles's exploit for webtester 5
Add a default Samsung community string

See http://www.kb.cert.org/vuls/id/281284

and

http://www.h-online.com/security/news/item/Samsung-network-printer-vulnerability-discovered-Update-2-1757967.html
Land #2537 - Add a default Samsung community string
Avoid extra slash in redirect URI

[SeeRM #8507]