Further enhance the check for needed tools:
- update the tool_pattern to use ' || ' as a pattern separator
- which allows using | in regexp
- add checks for cut and xargs
- manually check for grep and sed because they are needed when checking for tools
- print why a test failed, with each tested tool and regexp
- move tools checks before options parsing
- apply conttibutions before computing the version string
- inform user to run make && make install

/trunk/configure | 173 111 62 0 ++++++++++++++++++++++++++++++++++++++++----------------------
1 file changed, 111 insertions(+), 62 deletions(-)

# x86_64 specific options

config ARCH_x86_64

    select ARCH_64

    select ARCH_SUPPORT_ARCH

    select ARCH_SUPPORT_CPU

    select ARCH_SUPPORT_TUNE

    help

      The x86_64 architecture, as defined by:

        http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_875_7044,00.html