from 2.4.6 to 2.4.7
- fixing memory allocation bug in crc class, that lead glibc aborting dar
- reviewed code and replaced some remaining occurences of bzero/bcopy by
  their recommended replacement version
- fixed compilation problem under Solaris
- fixed bug that could lead a file to be wrongly reported as different from the
  one on filesystem, when that file has been changed while it was saved, then
  saved a second time but has its size modified since the first time it was
  saved.