Fix windows crash in FOREACH_PARAM, due to accessing non-existent element
in the vector.
Optimize warning() opcode
Add a max_warnings_per_thread attribute which makes the warning opcode cheaper by skipping all processing after warning has been called a certain number of times (regardless of the warning to be printed).
When this option is 0, the warning opcodes can be optimized away completely resulting in the fastest possible performance.
Fix for freebsd 8.2 compile
Better fix for old GCC versions that give a conflict between IF token used for
parsing and a template in boost headers with the same name.
Add option to disable using embedded LLVM bitcode, in case building it with
clang++ is not possible for some reason. On by default except on Windows
where it was already disabled.
Clarify CC license of docs
Clean up spec, especially discussion of closures
Docs -- overhaul suggested metadata conventions to align with Katana.
CHANGES update
Rebuild spec PDF
Don't error/warn if metadata name masks a global scope name. Who cares?

This came up after the recent change in published metadata conventions --
we now recommend 'min' and 'max', which were generating spurious errors.
Change example shader metadata to conform to new recommendations.
And a couple other minor formatting or bug fixes.
Another fix for windows crash with FOREACH_PARAM, it was still accessing an
element beyond the end of the vector which could crash.
Add query_closure() to shadingsys
CHANGES
Bump versions now that we've branched 1.3
New ShadingSystem attribute "renderer_outputs" enumerates the renderer outputs
(AOVs) explicitly, so that elision of unused outputs can be done with
full understanding of which params will or will not be used.
Beware: if you use "opt_elide_unconnected_outputs", you MUST pass
"renderer_outputs" or your outputs may be eliminated!