added ZeroShell RC2 RCE
changes made to zeroshell_exec according to suggestions
Use default send_request_cgi timeout
Fix typo
Do not fail_with on method used from check
Whoops on trailing commas
Fix References field
Use snake_case
Do not get a session on every execute_command call
Land #2409, @xistence exploit for ZeroShell
Typo in module name
Not actually a typo

Turns out, the object name is "CCaret," though we're talking about the
"caret." Confuz0ring!