Log Message:
Make pkgtools/digest cross-compilation ready and actually improve
portability somewhat:
- consistently use POSIX uint{8,16,32,64}_t throughout the code.
- asssume for now that the compiler supports ULL as suffix
- use AC_TYPE_UINT{8,16,32,64}_T instead of bits.c to compute
  possible replacement types.

Bump to 20070703. Tested by Thorsten Glaser on Interix and tnn@ on
Solaris.