Throw error if relationship reverse is misconfigured
Add unset() support to model and ::reset() to instrumented list
orm: Refactor WHERE clause compilation
orm: Add bulk update compilation
orm: Fix setup of InstrumentedList magic properties
orm: Fix magic lookup of one-to-one relations
orm: Add ::count() and ::expunge() to InstrumentedList
Merge pull request #747 from greezybacon/issue/orm-revisited

orm: Add several new gizmos and fix a few small issues

Reviewed-By: Peter Rotich <peter@osticket.com>