WebDevStudios/CMB2 — pull request #70 by trelvox (2014-11-01 12:34:29+00:00)
Title: Improve field arguments to make files always accessible by ID

BUGREPORT
$this->field->object_type() : expected return -> (custom) Posttype : actual return -> false (always)
$this->field->object_id() : expected return -> (custom) Post-ID : actual return -> false (always)
both methods are not implemented, __call fallback accesses wrong properties
Postmeta READ always fails (no ID/type), fallback using GUID fails on edited/moved attachments
http://pods.io/2013/07/17/dont-use-the-guid-field-ever-ever-ever/
RESULT: missing images on e.g. edit.php ( for GUID != filename )
FIX: replace function calls with simple properties