Cleanup VertexBuffer ifdefs
Copying out platform versions of VertexBuffer.
Deduplicating platform code in VertexBuffer
Extracted platform methods from IndexBuffer.
Platform copy for IndexBuffer.
IndexBuffer platform code split.
Fix for PSM
Fix index buffer usings for GLES
Fix ifdef for GLES
Merge pull request #2259 from SickheadGames/VBIBSplit

Split VertexBuffer/IndexBuffer on a per-API basis