fix select level screen, and change dialog a little
fix dialog
create assets for stage4
create object, shape, and stage builders for stage4
fix assets
clean up: remove foundation
create gravity block
fix gravity box problem (temporarily)
connect 2 gravity blocks
fix item panel and keep gravity block from going out stage
finish stage4-1
create gravity ball
improve destroying code
solve gravity ball stuck problem
finish stage5 levels
use locale for writing object data
fix assets
create message box and fix some bugs
fix dialog
group the managers, create auto hide message, and put sound to drop button