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>

mainmenu "The crosstool-NG configuration menu"

source "config/configure.in"

source "config/backend.in"

source "config/global.in"

source "config/target.in"

source "config/toolchain.in"

source "config/kernel.in"

source "config/binutils.in"

source "config/cc.in"

source "config/libc.in"

source "config/debug.in"

source "config/companion_libs.in"

source "config/companion_tools.in"

source "config/test_suite.in"