Added missing revision note.

This is for issue #19.
Revised media.

This is for issue #19.
Removed import Modelica.Constants statement.
Added missing extends Modelica.Icons.Function statement.
Removed computation in h_pTX and in T_phX of properties that are not
used.
Revised media.

This is for issue #19.
Used different medium so that model passes the model check without
error.
Removed import Modelica.Constants

This is for issue #19.
Changed the mode of the file to 100644.

This is for issue #19.