Basic working on-demand julia demo.  Stuff works, but not well.  The biggest issues still extant are that the spark job web page doesn't work (so we can't see how things are going), and request caching and combining doesn't seem to be working.
Fix case problem when reading client tile request parameters.
Merge branch 'develop' into on-demand-regressions
Merge pull request #70 from oculusinfo/on-demand-regressions

On demand regressions