Fix missing osl_fmod_vvf and dual functions on Windows.
Nicer debug printing when op doesn't have an associated source line
Avoid incorrect heap addressing when retrieving a symbol's address
oslc now gives a compile error when trying to use a function as a variable,
previously it would output non working bytecode.
Fix missing output of shader parameters when returning from a block.

Early 'return' was jumping to the exit_instance_block, but we were
incorrectly putting the code that copies output variables to their
destination layer before this block, rather than after.  The solution
is to do the output copying after that jump point.
Get rid of TBB references
Bug fix -- filterwidth() wasn't properly enforcing that it needs derivs.
Also remove type checking table entry for aastep, which was never implemented.
CHANGES, rebuild docs, bump version for 1.3.2