scripts/functions: force extract folder to archive basename

Some archives like those of the 2011.07 revisions of Linaro GCC contain a folder
name different from the archive basename, which leads to errors afterwards, e.g.
when patching. E.g.:
gcc-linaro-4.5-2011.07.tar.bz2 extracts to gcc-linaro-4.5-2011.07-0/

This patch changes CT_Extract() to force the extraction of all archives to a
folder named like the archive basename. E.g.:
gcc-linaro-4.5-2011.07.tar.bz2 now extracts to gcc-linaro-4.5-2011.07/

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

 --- trunk/src/acos.c	2009/12/08 16:49:43	733

 +++ trunk/src/acos.c	2009/12/09 20:51:38	734

 @@ -188,10 +188,7 @@

    else

      rnd_im = rnd_im == GMP_RNDU ? GMP_RNDD

        : rnd_im == GMP_RNDD ? GMP_RNDU

 -#if MPFR_VERSION_MAJOR >= 3

 -      : rnd_im == GMP_RNDA ? GMP_RNDZ

 -#endif

 -      : rnd_im;

 +      : rnd_im; /* both RNDZ and RNDA map to themselves for -asin(z) */

    rnd1 = RNDC(GMP_RNDN, rnd_im);

    mpfr_init2 (pi_over_2, p);

    for (;;)