Made a trickling resources animation

Resources counters now roll up or down to their correct value, rather
than jumping instantly.
Build Progress Bars

Added build progress bars to all visible structures. This functionality
can be found in the Hud class.
Button Graphics Fixed

Fixed the small button graphics so that they do not get stretched.
Selection Indicators

Added simple white boxes around any selected unit.
Added Health Bars

Health bars have been added to all visible or friendly units.
RF