Enhance ./configure tools checking.
Add check for compatible autoconf.

/trunk/configure | 95 61 34 0 ++++++++++++++++++++++++++++++++++++++++----------------------
1 file changed, 61 insertions(+), 34 deletions(-)

# x86 specific options

config ARCH_x86

    select ARCH_SUPPORT_ARCH

    select ARCH_SUPPORT_CPU

    select ARCH_SUPPORT_TUNE

    help

      The x86 architecture, as defined by:

        http://www.intel.com/