added defaultMinificationFilter and defaultMagnificationFilter to ImageryProvider
added defaultMinificationFilter and defaultMagnificationFilter to ImageryProvider

likangning93/cesium,AnalyticalGraphicsInc/cesium,wallw-bits/cesium,likangning93/cesium,oterral/cesium,ggetz/cesium,wallw-bits/cesium,oterral/cesium,AnalyticalGraphicsInc/cesium,NaderCHASER/cesium,progsung/cesium,CesiumGS/cesium,soceur/cesium,YonatanKra/cesium,likangning93/cesium,CesiumGS/cesium,emackey/cesium,jasonbeverage/cesium,YonatanKra/cesium,emackey/cesium,hodbauer/cesium,wallw-bits/cesium,likangning93/cesium,emackey/cesium,geoscan/cesium,kaktus40/cesium,wallw-bits/cesium,YonatanKra/cesium,geoscan/cesium,jasonbeverage/cesium,likangning93/cesium,CesiumGS/cesium,ggetz/cesium,oterral/cesium,kaktus40/cesium,josh-bernstein/cesium,hodbauer/cesium,hodbauer/cesium,CesiumGS/cesium,ggetz/cesium,NaderCHASER/cesium,NaderCHASER/cesium,YonatanKra/cesium,soceur/cesium,emackey/cesium,progsung/cesium,soceur/cesium,CesiumGS/cesium,josh-bernstein/cesium,ggetz/cesium