Enhanced makedeb script so it will automatically detect the python/ruby/qt version

scripts/makedeb.sh

@@ -43,7 +43,35 @@ bindir="bin.linux.release"
 builddir="build.linux.release" 
 libdir="/usr/lib/klayout"
 
+qmake="qmake"
+if which qmake-qt5; then
+  qmake="qmake-qt5"
+elif which qmake-qt4; then
+  qmake="qmake-qt4"
+elif which qmake; then
+  qmake="qmake"
+fi
+
+ruby="ruby"
+if which ruby2; then
+  ruby="ruby2"
+elif which ruby; then
+  ruby="ruby"
+fi
+
+python="python"
+if which python3; then
+  python="python3"
+elif which python2; then
+  python="python2"
+elif which python; then
+  python="python"
+fi
+
 ./build.sh -j4 \
+           -qmake $qmake \
+           -python $python \
+           -ruby $ruby \
            -bin $bindir \
            -build $builddir \
            -rpath $libdir \