Allow selecting 'latest' snapshot, as well as 'specific' date snapshot for glibc.
Update uClibc config to commonalise some help.

/trunk/scripts/build/libc_glibc.sh | 22 20 2 0 ++++++++++++++++++++--
/trunk/config/libc/glibc.in | 12 12 0 0 ++++++++++++
/trunk/config/libc/uClibc.in | 12 4 8 0 ++++--------
/trunk/config/libc.in | 13 13 0 0 +++++++++++++
4 files changed, 49 insertions(+), 10 deletions(-)

 --- gcc-4.0.0/libstdc++-v3/configure-old	2005-04-30 22:04:48.061603912 -0500

 +++ gcc-4.0.0/libstdc++-v3/configure	2005-04-30 22:06:13.678588152 -0500

 @@ -7194,6 +7194,9 @@

  cat >>conftest.$ac_ext <<_ACEOF

  /* end confdefs.h.  */

  #include <complex.h>

 +#ifdef __UCLIBC__

 +#error ugly hack to make sure configure test fails here for cross until uClibc supports the complex funcs

 +#endif

  int

  main ()

  {