Fixing up examples for 5.0 & Live DDL

1 commit per app (I'm getting better at this).
Remove VoltCache.
Update lots of readme files to use markdown and to push for liveddl.

I think these could use another pass before 5.0 to try to simplify further, but this should be a step in the right direction.
The docker demo image doesn't have JDK installed. Things are precompiled prior to packaging them into the image. That's why the check.