Recognise bash-4 as a usable bash.

Spotted by "Kim B. Heino" <Kim.Heino@bluegiga.com>

 /trunk/configure |    7     3     4     0 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

configure

@@ -25,21 +25,20 @@ DATE=$( date +%Y%m%d )
 # Examples:
 #    bash:bash=^GNU bash, version 3\.
 #     - if ${bash} is set and non-null, does nothing
-#     - else ensures that bash exists in the PATH, and that
-#         "$( "$( which bash )" --version |head -n 1 )"
+#     - else ensures that bash exists in the PATH, and that $( bash --version )
 #       matches the regexp '^GNU bash, version 3\.'
 #       - if so, then sets bash="$( which bash )"
 #    autoconf=(GNU Autoconf) || autoconf2.50
 #     - does not look at an existing variable
 #     - ensures that:
-#         - 'autoconf' is to be found in the PATH, and that $( autoconf --version |head -n 1 )
+#         - 'autoconf' is to be found in the PATH, and that $( autoconf --version )
 #           matches the regexp '(GNU Autoconf)' (which btw is the signature of
 #           autoconf >= 2.50),
 #       OR that:
 #         - 'autoconf2.50' is to be found in the PATH
 #
 TOOLS_TO_CHECK='
-bash:bash=^GNU bash, version 3\.
+bash:bash=^GNU bash, version [34]\.
 cut
 xargs
 install:install=GNU coreutils