all: unmark experimental version

It's been a while we've had those versions, time to unmark them being
experimental. It does not mean everything is perfect, but may gather
some more testing on those versions.

Update samples accordingly.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

CT_EXPERIMENTAL=y

CT_LOCAL_TARBALLS_DIR="${HOME}/src"

CT_SAVE_TARBALLS=y

CT_LOG_EXTRA=y

CT_ARCH_s390=y

CT_KERNEL_linux=y

CT_KERNEL_V_2_6_31_14=y

CT_BINUTILS_V_2_20_1a=y

CT_CC_V_4_3_4=y

CT_CC_LANG_CXX=y

CT_LIBC_glibc=y

CT_LIBC_GLIBC_V_2_9=y

CT_GMP_V_4_3_2=y

CT_MPFR_V_2_4_2=y