Remove CZML backwards comapatibility code

We'll be standardizing on CZML 1.0 in the upcoming release and will only support 1.0 and newer going forward.
Fix specs and sample data after remove BC CZML code.
Update test data with regenerated czml files.
Start refactoring CZML to mandate versioning

This change breaks most CZML processing for now.  Also clean up some misc doc issues.
Ongoing CZML versioning work

1. Refactor how clock/name are processed.
2. Throw when the first packet is not a document object or is missing version.
3. Update specs.
Merge remote-tracking branch 'origin/master' into czml-cleanup
Merge branch 'czml-cleanup' into czml-versioning
And CZML versioning tests and fix bugs uncovered by them.
Changes after review.
Fix CZML.
Merge pull request #1947 from AnalyticalGraphicsInc/czml-versioning

CZML versioning
Merge remote-tracking branch 'origin/master' into gltf-8