WMTS Support addition
gcebelieu is a new cesium contributor.
WMTS support for 1.01 release in CHANGES.md
JSHint errors fix
revert changes to revert
renaming WMTSImageryProvider into WebMapTileServiceImageryProvider
default parameters management review.
Do really delete WMTSImageryProvider.js and WMTSImageryProviderSpec.js
Addition for what is supported or not by WebMapTileServiceImageryProvider (cf. https://github.com/AnalyticalGraphicsInc/cesium/pull/1988/files#r15667738)
rename WebMapTileServiceImageryProviderSpec.js
writing Spec Stuff for WebMapTileServiceImageryProvider
adding getter for "format" property.
removing unused variable defaultCredit
Merge pull request #1988 from gcebelieu/wmts

WMTS Support addition
Minor tweaks to WMTS provider.

* Clean up documentation slightly.
* Rename `tms` constructor parameter to `tileMatrixSetID` to avoid abbreviation.
* Use a USGS WMTS server in the example in the docs instead of the French one, because the USGS one does not require a key.
* Add WMTS example to Sandcastle "Imagery Layers Manipulation" example.
Fix typo.
Merge pull request #2022 from AnalyticalGraphicsInc/wmtsTweaks

Minor tweaks to WMTS provider.