The terminal has a lot of bits that may be worth reusing outside the
single implementation. Those bits are now located at 'include/terminal'
in the gems repository.
sgr0 is currently implemented as a wrapper of sgr(0) which
seems to work fine.
For now we accept but ignore certain sgr sequences like for
example [0;10;1m which is generated by lynx even when using
TERM=linux (I am not sure yet if that's actually valid at all).
