[duneproject][Bugfix] Make sure dune_enable_all_packages() can actually be disabled

The shell script logic for switching dune_enable_all_packages() on or
off in duneproject was broken and always turned the feature on, ignoring
the user input.

Fixed by testing for the actual contents of the variable instead of its
length and by converting the contents to lowercase before.

bin/duneproject

@@ -245,6 +245,10 @@ while [ "$DATACORRECT" != "y" -a "$DATACORRECT" != "Y" ]; do
   fi
 done
 
+# canonicalize contents of ENABLE_ALL
+ENABLE_ALL=$(tr '[:upper:]' '[:lower:]' <<< "$ENABLE_ALL")
+
+
 echo
 echo "A sample code $MODULE.cc is generated in the \"$PROJECT\" directory."
 echo "Look at the README and dune.module files there."
@@ -506,7 +510,7 @@ include(DuneMacros)
 # start a dune project with information from dune.module
 dune_project()
 M_DELIM
-if test ! -z "$ENABLE_ALL"; then
+if [ 'y' == "$ENABLE_ALL" ] ; then
 cat>> "$PROJECT/CMakeLists.txt" << M_DELIM
 dune_enable_all_packages()
 M_DELIM