substitue non-portable tail command with sed.

bld/get-version

@@ -18,7 +18,7 @@ else
      vers=`cat $1/VERSION | sed 's/[(), ]/,/ g' | tr ',' '\n' | grep $v[0-9]`
 
      if [ $? -eq 0 ]; then
-         echo "${vers}" | head -n 1 | tail -c +2
+         echo "${vers}" | head -n 1 | sed 's/^v//'
      else
          cat $1/VERSION
      fi