[kepler-dev] Additional cleanup of icons for impending release.

[Kevin Ruland]

I noticed that the _svgIcon attribute is assigned some relative filename 
like:

../kepler-docs/dev/usability/graphics/svg/basic-actor.svg

and the _thumbnailRasterIcon an absolute filename like:

/actorthumbs/basic-actor-sm.gif

I suspect these are both loaded use the class loader via 
getResourceAsStream() or something, but it makes sense to me that we 
distribute all these resources consistantly.  We should make a single 
jar ( kepler-icons.jar ?) which contains all of them and use some 
consistant naming like:

/thumbs/basic-actor-sm.gif
/svg/basic-actor.svg

Or even:

/basic-actor-sm.gif
/basic-actor.svg

If the names won't clash without the directory name.  I suspect the 
names do not clash.

This has one additional benefit that to change all the icons, you just 
need to drop in a different jar.

Kevin