corrected VSM calculation
added Scene#isSelfShadowSupported and removed ILight#hasFloatTexture
renamed method names (depthTexture to shadowMap)
shadow map now uses SimpleShadowMap, delete order sort to Project class
fixed a bug "no shadow" cannot be activated
added reference implementation (related with effect) to BaseRenderContext
fixed compile errors because of libvpvl2 changes
added order support to Project class
fixed a bug that causes crash after reloading project and cleanup