New Cesium packaging via makZipFile changes

1. The original zip file is still created, but now known as Cesium-amd-<version>.zip
2. A second zip file is also created, Cesium-<version>.zip.  This new zip contains only the minified Cesium, Assets, Documentation, and a new skeleton.
3. The new skeleton doesn't require a build process and simply creates the 3 main widgets on an empty globe (though we can change this).
Merge branch 'master' into packaging
Forgot to rename old zip file.
Move skeleton.html build logic into `combine` target.
Simplify skeleton and rename it to HelloWorld.
Merge remote-tracking branch 'origin/master' into packaging
Fixes from my last commit.
Simplify fileset.
Rename larger zip package to Cesium-full-<version>
Merge pull request #584 from AnalyticalGraphicsInc/packaging

New Cesium release packaging