Read/modify/update optimization on properties

[ghost]

Looks like it is sometimes possible to eliminate calls to update_property because read_property does not separate the returned value.

The idea is described in this test case and is implemented in Phalcon\Mvc\Router\Route::construct().

The result is:

• directly saved 80 bytes of RAM (amd64)
• -2 or -3 variables tracked by the MM
• eliminated call to update_property.

If you are OK with this optimization, I think there are places where this can be implemented.

[phalcon]

I think this makes the logic a bit strange to be understood by PHP developers since they might have to deal directly with refcounts. I think we can better introduce a new function in kernel/object to increment static properties (involving refcount so as reducing the memory usage).