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).
