Script to simplify maintenance of sysproperties

This procedure will maintain the sysproperties table by wrapping system procedures:
                • sp_addextendedproperty
                • sp_dropextendedproperty
                • sp_updateextendedproperty
            The parameters are:
                • @object    --    primary name of the object being to be maintained.
                • @column    --    column or parameter name [optional].
                • @property    --    name of the property.
                • @value    --    description associated with the property.
                • @action    --    save or delete.

Usage  :    exec sp__SysProperties_sav 'FK_ForeignKey', null, 'MS_Description', 'this is a foreign key', ['save']
-- add a property to a parameter
sp__SysProperties_sav 'my_proc', '@some_param', 'MS_Description', 'this documents a parameter', ['save']
-- removed the property
sp__SysProperties_sav 'my_proc', '@some_param', 'MS_Description', null, 'delete'

I haven't figured out indexes or user types --- yet.