Make next_screen static and add a comment.
tree19c9b08605d7b3a452ce0a1a447e2491dbc0acd0
drwxr-xr-x - apps
drwxr-xr-x - backdrops
drwxr-xr-x - bootloader
drwxr-xr-x - docs
drwxr-xr-x - firmware
drwxr-xr-x - flash
drwxr-xr-x - fonts
drwxr-xr-x - gdb
drwxr-xr-x - icons
drwxr-xr-x - manual
drwxr-xr-x - rbutil
drwxr-xr-x - tools
drwxr-xr-x - uisimulator
drwxr-xr-x - utils
drwxr-xr-x - wps