Removed unused macro.
PHP-1297: Fixed off-by-one error.

This prevents uninitialised read valgrind errors (with USE_ZEND_ALLOC=0). It
however also makes var_dump() of the whole object also (correctly) show
deprecation warnings though. I'll be fixing that in the next commit.
Make sure that if we're dumping the whole object, we don't show deprecated warnings for properties.

Conflicts:
	mongoclient.c
Use PHP_VERSION_ID, as that's less fragile.
Merged pull request #782