Added new *Access objects for bed height calculation and flow velocity calculation; removed methods for specific data access from MINFOArtifact. flys-artifacts/trunk@4859 c6561f87-3c4e-4783-a992-168aeb5c3f6f

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