Remove Fedora 19 as supported distribution

Fedora 19 will reach its end of life on 6-JAN-2015

  https://lists.fedoraproject.org/pipermail/announce/2014-December/003243.html

Remove it as a supported distribution and add Fedora 21

  - stack.sh: Remove Fedora 19 from list of 'supported' distributions.
  - tools/fixup_stuff.sh: Remove Fedora 19. Also remove the workaround
    of disabling firewalld for Fedora 21.

Change-Id: If92b87d2f9a2bb95469730cda201a7981670f727
diff --git a/tools/fixup_stuff.sh b/tools/fixup_stuff.sh
index 26aae82..c7f1efa 100755
--- a/tools/fixup_stuff.sh
+++ b/tools/fixup_stuff.sh
@@ -111,8 +111,8 @@
     fi
 
     FORCE_FIREWALLD=$(trueorfalse False $FORCE_FIREWALLD)
-    if [[ ${DISTRO} =~ (f19|f20) && $FORCE_FIREWALLD == "False" ]]; then
-        # On Fedora 19 and 20 firewalld interacts badly with libvirt and
+    if [[ ${DISTRO} =~ (f20) && $FORCE_FIREWALLD == "False" ]]; then
+        # On Fedora 20 firewalld interacts badly with libvirt and
         # slows things down significantly.  However, for those cases
         # where that combination is desired, allow this fix to be skipped.