[Etoys] text rendering

[Yoshiki Ohshima]

  Alan and everybody,

  I pushed two change sets that deal with some inefficiency in text
rendering.  Some are already known issues around the recalculation of
some properties and some are a bit or tidying up of code.  Most
notably, True Type font rendering is much faster now.

  I still think the use of True Type should be somewhat limited, but
for making splash screen or that kind of thing, it should be ok to use
it if it doesn't change color of characters in a text (as much), and
don't other stuff overlap with text (as much).

-- Yoshiki