Improve clarity.

 Changes between 0.9.4 and 0.9.5  [xx XXX 1999]

  *) RAND_load_file(..., -1) reads the complete file and uses it to

     seed the PRNG (previously an explicit byte count was required).

     The bytes obtained by stat() are no longer counted for the

     return value.

     [Bodo Möller, Ulf Möller]

  *) The return value of RAND_load_file() no longer counts bytes obtained

     by stat().  RAND_load_file(..., -1) is new and uses the complete file

     to seed the PRNG (previously an explicit byte count was required).

     [Ulf Möller, Bodo Möller]

  *) Clean up CRYPTO_EX_DATA functions, some of these didn't have prototypes

     used (char *) instead of (void *) and had casts all over the place.