lots of cleanup work on screens -- note, buttons get 'changeListeners',
not 'clickListeners' (they already have one)
cleanup layout screen click listeners/button enable/disable flags
cleanup ship layout screen and widget
clean up ship layout screen  
add backgrounds to non-play screens
more cleanup of ship layout screen -- next up, inventory screen
rework inventory screen to conform to other guis -- still needs table
cleanup
adapt inventory screen for item selection, removed inventory
selection window