IMPORTANT: Making prev. Memcached_DataObject working again with schemaDef

IMPORTANT: Making prev. Memcached_DataObject working again with schemaDef

Lots of the Memcached_DataObject classes stopped working when upgraded to
Managed_DataObject because they lacked schemaDef().

I have _hopefully_ made it so that all the references to the table uses
each class' schemaDef, rather than the more manual ColumnDef stuff. Not
all plugins have been tested thoroughly yet.

NOTE: This is applied with getKV calls instead of staticGet, as it was
important for PHP Strict Standards compliance to avoid calling the non-
static functions statically. (unfortunately DB and DB_DataObject still do
this within themselves...)