add missing developer errors
Shader compile/link tweak
add tests for dev errors
cleanup
Added xdefineSuite
Fix using texture from another context in billboard collection tests
Merge pull request #1314 from AnalyticalGraphicsInc/xdefine

Added xdefineSuite
Merge pull request #1312 from AnalyticalGraphicsInc/extentGeoDevError

Add missing developer errors to ExtentGeometry
Fixed texture atlas creation
Added back deleteProgram
Merge pull request #1313 from AnalyticalGraphicsInc/shadertweak

Minor shader compile/link performance improvement
Merge pull request #1315 from AnalyticalGraphicsInc/testfixes

Minor test fixes
Merge remote-tracking branch 'origin/master' into gltf