Give Scene frameState, camera, and screen space camera controller initial state before rendering.
Consolidate .gitignore files in the root.

This makes it easier to copy various source folders for use in other projects without accidentally ignoring items.
Merge pull request #991 from AnalyticalGraphicsInc/consolidateGitIgnore

Consolidate .gitignore files in the root.
Merge pull request #986 from AnalyticalGraphicsInc/initialSceneState

Initial Scene state.
Merge branch 'master' of https://github.com/AnalyticalGraphicsInc/cesium into googleEarth