[C2hs] patch applied (c2hs): Apparently ' \f' and ' \v' are allowed in C strings and char literals

[Duncan Coutts]

Sun Apr 15 00:58:32 PDT 2007  Duncan Coutts <duncan.coutts at worc.ox.ac.uk>
  * Apparently '\f' and '\v' are allowed in C strings and char literals
  According to both gcc and the C99 spec.
  Some odd programs really use it too, like flex and binutils.

    M ./c2hs/c/CLexer.x -2 +2