convert PerformanceDisplay from canvas to div
update cesium viewer for changes
Merge branch 'master' into performanceDisplay
update style
update cesium viewer
update doc
Merge branch 'master' into performanceDisplay

Conflicts:
	CHANGES.md
update api
changes.md
Tweak CHANGES.md
add test
Merge branch 'master' into performanceDisplay

Conflicts:
	CHANGES.md
spelling
create textnodes
Merge pull request #1425 from AnalyticalGraphicsInc/performanceDisplay

Performance display
Change view extent back to using the geocentric normal instead of the geodetic normal.
Merge pull request #1426 from AnalyticalGraphicsInc/viewExtent

View Extent
Tweak CHANGES.md
Update build.xml to b25
Merge remote-tracking branch 'origin/master' into meshTerrain

Conflicts:
	CHANGES.md