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(-)

 #!/bin/sh

 SKIP_ME="### CT_NG SKIP ME ###"

 skip_me=$(($(cat "${0}" |grep --binary-files=text -o -b -E "^${SKIP_ME}$" |cut -d : -f 1)+${#SKIP_ME}+1))

 dd if="${0}" bs=${skip_me} skip=1 2>/dev/null |bzcat

 exit 0

 ### CT_NG SKIP ME ###