Ticket #395: Add post::loadFromIdentityMap() callback to fActiveRecord

Right now this is pretty much the only place where returned record can't be modified. The solution I'm working on now depends on it's own properties that don't get transferred when the record is loaded from the identity map.

The whole object with all the extra properties is actually stored in the identity map, they just don't get copied over. With this callback I get a chance to copy over whatever other stuff I might need from the identity map.

The code for it is simply

fORM::callHookCallbacks(
    $this,
    'post::loadFromIdentityMap()',
    $this->values,
    $this->old_values,
    $this->related_records,
    $this->cache,
    $object
);

which is added to the end of loadFromIdentityMap(). I've tried it and it works great. Since loadFromResult() has a callback I'm really hoping loadFromIdentityMap() can get one too.