This was intended to be used to simultaneously support the cheat mode dialog with all the inventory items. But that is going to need to be implemented as a completely separate dialog.
This makes the code use Common::List for all cases where synchronization can
not be done with tSage::List::synchronise. Furthermore I renamed the custom
List class to SynchronisedList to stress its purpose.
I also removed clear2, contains and forEach and replaced them with algorithm
usage from Common:: or in the case of "contains" replaced them with a simple
inline function which uses Common::find.
