bug in documentation

[Paul Zimmermann]

The documentation of mpf_set_str says:

     The argument BASE may be in the ranges 2 to 36, or -36 to -2.
     Negative values are used to specify that the exponent is in
     decimal.

then:

     Unlike the corresponding `mpz' function, the base will not be
     determined from the leading characters of the string if BASE is 0.

Maybe the first sentence should read:

      The argument BASE may be in the ranges 2 to 36, or -36 to -2, or 0.
      [...]

Paul