Moved pre/post __set/__isset/__unset functionality into call_*
functions.

This allowed accessors to take advantage of their use/needs. Also
cleaned up the horribly formatted if() statement that is nearly
identical in all read/write/has/unset object functions.
Merge branch 'accessors' of github.com:cpriest/php-src into accessors

Conflicts:
	Zend/zend_object_handlers.c