Changed drupalgap_attributes() to allow empty attributes.
Added form.disabled feature to the Forms API.
#213. Changed drupalgap_entity_add_core_fields_to_form() to use the elements returned from drupalgap_entity_get_core_fields() rather than rebuilding them. Removed all the code from the deprecated function drupalgap_entity_assemble_data(). Changed drupalgap_entity_get_core_fields() to better handle comment settings.
Updated binary.