[PATCH] Converting accesses to refcount and is_ref to macros

This patch is a simple, albeit widespread change that converts access to zval.refcount, zval.is_ref, _object_store.refcount to macros. There is no functional change to the code, but this will make it easier to implement a garbage collector in the future. This patch was too large to attach to the e-mail message. It is available at: http://web.pdx.edu/~way/macropatch.diff.txt Yiduo (David) Wang