Switch to Fedora-x86_64-20-20140618-sda

The heat-slow job using the Fedora-20 image as L2 guest, the
currently used version is affected by the heartbleed issue and
the Mb-Bios bug issue observed with emulation.

This version of the  Fedora cloud image uses the no_timer_check
kernel parameter, which solves the MP-Bios Bug issue.

The Image tested with ~3000 heat-slow job, without any issue.

Change-Id: I9ce9b7769c2d91e630b0362f2c2c6ac9066defbc
Closes-Bug: #1312199
Closes-Bug: #1297560
Add libyaml-devel package dependancy

Without libyaml-devel package installed (on Fedora-20),
running ./stack throws:

  [. . .]
  build/temp.linux-x86_64-2.7/check_libyaml.c:2:18: fatal error: yaml.h:
  No such file or directory #include <yaml.h> ^ compilation terminated.

  libyaml is not found or a compiler error: forcing --without-libyaml
  [. . .]

Adding this dependency to files/rpms/general resolves it. Also added to
files/apts/general.

Change-Id: If1aa23bf3fc76ea2b321c3725dd07050ddd4b825
Merge "Switch to Fedora-x86_64-20-20140618-sda"
Add ability to enable OSprofiler

To enable OSprofiler we should be able to add "profiler" notification
topic to ceilometer notification topics.

More about OSprofiler:
https://github.com/stackforge/osprofiler

More about ceilometer plugin:
https://review.openstack.org/#/c/100239/

Sample of trace (via Cinder and Nova Services):
http://pavlovic.me/rally/profiler/

Change-Id: I6137174a3ecddd58f62e0f98b235b71b1c070f13
Merge "Add ability to enable OSprofiler"
Merge "Add libyaml-devel package dependancy"
Merge branch 'master' of https://github.com/openstack-dev/devstack