Add SamlServlet to implement actual login via SAML Ticket. This is the main part of single-sign-on for flys from issue1265. SamlServlet is an adapted copy of LoginServlet. The code shared by both classes will be extracted into a base class later.

SYMBOLSET
SYMBOL
  NAME 'point'
  TYPE ELLIPSE
  POINTS
    1 1
  END
  FILLED TRUE
END
SYMBOL
  NAME "square"
  TYPE VECTOR
  POINTS
    0 0
    0 1
    1 1
    1 0
    0 0
  END
  FILLED TRUE
END
END