Changeset 7 for trunk/gui/scripts

Created an initial EnergyLevels? viewer and MoleculeViewer?. The
MoleculeViewer? is integrated into the driver, but the EnergyLevels?
is not. The material library file contains some new properties
for the appearance of atoms, and the MoleculeViewer? uses this.
Both energyLevels.tcl and moleculeViewer.tcl still have some
driver code at the bottom of the files, so you can run them as
a single file, by themselves, for testing. This code should be
removed when we get further along.