BuffDuration Updates

-Added default Extend.xml entries for common brd songs
-Added default Extend.xml entires for all-songs, composure, and enhancing
magic duration gear
-Added support for multiple pieces of gear enhancing one effect
-Added effect of composure enhancing gear on others
-BRD song timers now maintain even after overwritten on self
-Indirect, status.xml now has many more default timers added