get rid of text experiment, switch to function pointers for signal connection
use more signal connections to implement specific behavior on ships.  make collision logic symmetric
Use OO more heavily, moving update position functionality to a base item class.  Make the diamonds a sub of the base item class, too.
add all items to same group, allow enemy ships to be destroyed by diamonds
increase screen size to nexus5
make world an item, use common base code
get rid of custom qworldview
remove extraneoius file
rename world to cave
Clean up cave physics/scene definition
clean up brush initialization.  Clean up Cave.
move body later in definition, since it's not really necessary.
move Diamond construction around.