Added BTBR to background types.  This probably shouldnt be hardcoded.
Added BTBR to background types.  This probably shouldnt be hardcoded.

davebridges/mousedb,BridgesLab/mousedb,BridgesLab/mousedb,davebridges/mousedb,BridgesLab/mousedb,davebridges/mousedb,davebridges/mousedb,BridgesLab/mousedb