Merge pull request #767 from seanpaultaylor/next

Cleaned up ParticlesGame sample04
Merge pull request #768 from seanpaultaylor/next

Next
Merge pull request #769 from seanpaultaylor/next

Minor cleanup to InputTest and TextureTest.
Fixed memory leak in Terrain.
Fixed incorrect default render state setting for depth write.
Merge pull request #770 from sgrenier/next

Fixed memory leak in Terrain.
Fixed positions for TextureTest