lua currently splashes a stack traceback on error
for deep tracebacks and especially on devices with smaller screens
this leaves out a lot of vital information
in the past I have resorted to splitting the traceback string or
even saving the return to a file
This patch provides a scrollable buffer with rudimentary text reflow
to allow you to read the whole traceback string
Upon traceback if you press nothing the screen will display for 5 seconds
If you press OK or CANCEL it will quit immediately
PREV/NEXT scrolls the list on button press timeout is disabled
lua now provides rb.splash_scroller(timeout, str)
example script provided too
Change-Id: Idbc8ce0c514196f0fae48c43aeaea8b60d6da1a5