Topic: Client r 474-475 changes

Converted all image files to PNG format, to provide new features like alpha channels and smaller patches.
Improved the look of ship thrust animation, they no longer "look washed out".

Amethyst        T0    Pyr     21
Cisco                T4    Sco    81
Delphi              T0    Eng    90
Neuropath      T0    Tel     10