RenderShaderPasses and FillDepthBuffer performance improvement

[Metzelmaennchen]

Currenty the RenderShaderPasses and FillDepthBuffer function are enabling vertex array attrib 1 and 5 for every drawn surface. Due to the fact that each of these surfaces need at least attrib 1 and 5 it makes sense to enable them once, draw all the surfs and disable them afterwards. Please have a look at following patch, it will drop a lot of redundant state changes and gain some performance: https://www.dropbox.com/s/jlg3ef0moy6xbr8/draw_common.patch?dl=0