Avoid drawing the fill bar our of the progress bar.
Avoid zero divided by zero that return 'nan' (Not a Number),
that does not bother lua code, but will crash libblitbuffer.so
when it gets nan as a coordinate.
* footer(optimize): remove dead code
* footer(fix): disable auto refresh time option when current time is not checked
* fix: support disable progress bar again
colors were a mixture of 4bpp integers (0=white, 15=black) and
fractional blackness levels (0=white, 1.0=black) before. This is
now unified to use the color specification of the Blitbuffer API.
As well as the width of the toc notches
Lower the default value of the container size a bit to avoid eating into
the last line on small borders setup (I checked on 167 & 212 DPI
devices, Feel free to revert to the previous value (19) if that causes
trouble).
