Servlet for handling CGI scripts
Example:
server.mount('/cgi/my_script', WEBrick::HTTPServlet::CGIHandler, '/path/to/my_script')
Creates a new CGI script servlet for the script at name
 
               # File webrick/httpservlet/cgihandler.rb, line 35
def initialize(server, name)
  super(server, name)
  @script_filename = name
  @tempdir = server[:TempDir]
  @cgicmd = "#{CGIRunner} #{server[:CGIInterpreter]}"
end