Fix projection doc
Merge pull request #1722 from AnalyticalGraphicsInc/docFix

Minor doc fixes
Merge remote-tracking branch 'origin/master' into projection-doc
Tweak doc
Removed =undefined for optional parameters
Use property getters for readonly properties in Renderer
Removed default credits when constructing the CesiumTerrainProvider. The Terrain Server will provide proper attribution.
Starting to fix array documentation markup for issue #1434
Merge pull request #1723 from AnalyticalGraphicsInc/undefined

Removed =undefined for optional parameters
Merge pull request #1721 from AnalyticalGraphicsInc/projection-doc

Fix projection doc
Merge pull request #1725 from abwood/terrainCredits

Removed default credits when constructing the CesiumTerrainProvider.
added new czm_depthRangeStruct and czm_depthRange constant.
fixed typo in capitalization
Merge pull request #1726 from gbeatty/glDepthRange

Gl depth range
Fix whitespace
Merge remote-tracking branch 'origin/master' into readonly-scene
More jsdoc fixes to our usage of Array.
More jsdoc Array fixes.
Check for missing parameters
Remove comments