Improve make_release script to optinally handle tagging and be more generic. It can now be used to prepare a fully configured version of flys. There are still some variables to set in the script or to be overwritten by environment variables.

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