When finding renderers in the cache, the stride of the current vertex
buffer object is also taken into account.

This fixes a problem where a renderer could be used to draw a
vertex buffer object with a different stride value than the renderer
captured when the renderer was created.
Merge pull request #956 from michaeljbishop/fix-stride-discrepancy-in-renderer-cache

Finding a renderer in the cache now takes into account the current VBO stride.