Fix another cases where compiler could assert with [] indexing on variables that
don't support it.
Throw compile error for int literals with values outside of the valid range,
instead of silently overflowing.

Also a fix for windows build where there is no unistd.h.
Fix compiler assert when compiling code that does closure color * closure color.
Fix compiler error with /usr/bin/cpp when stdosl.h is in a path with spaces.
Fix compiler error with boost::wave when no stdosl.h path is specified.
Tests for oslc indexing non-array, closure * closure multiplication and
int literal overflow errors.