RendererServices - add a ShaderGlobals* param to all matrix retrievals.

Some renderer implementations may find it really handy to have the SG
available (and maybe the void* renderstate contained in the SG) in order
to find the right matrices. (For example, allowing per-object
name-matrix bindings.)
RendererServices - change void *renderstate to ShaderGlobals *.

Most RendererServices functions take a ShaderGlobals *, but for
historical reasons (i.e. accretion), just a few took an opaque void
*renderstate.  Since the ShaderGlobals structure contains a renderstate
pointer within it, and some renderer implementations might want other
items within the SG to do their work, it seems like the more general
(not to mention uniform) apporach is to always pass the SG around.
Boost seems to need -lrt for >= 1.55
CHANGES update