Support option for Keystone PKIZ token provider

Keystone added support for a compressed token provider, PKIZ. This
change adds support to devstack. Set the KEYSTONE_TOKEN_FORMAT
option to "PKIZ" to configure Keystone to use it.

Change-Id: I123eef661c85cc805e950f1179b48e885078d40f
Reserve Keystone ports from the ephemeral range

Reserve Keystone ports from the ephemeral range as early as reasonably
possible in the fixup_stuff.sh process to reduce the likelihood that the
port will be in use. This does not completely resolve the issue
where Keystone's IANA assigned port falls into Linux's ephemeral
range, but this should reduce the occurrences. The default ports
are 35357 and 35358.

Change-Id: I8cfb53d8f90c1ff1fb1083c59fefabca3d14323b
Partial-Bug: #1253482
Cut the heat flavor

1024Mb memory is too much for single instance.
approximately 4 GiB memory used even without a booted VM.

The heat auto-scaling scenario needs to boot 3 VM
(currently disabled), if any other test running in parallel
and boots up a vm it would easily can cause OOM an
issue.

The heat-slow job can work with 128 MiB instance memory,
but this change reduces it just to 512 MiB (safer for the guest),
and enough to avoid OOM issues on the host,
and let us to heve more vm at the same time.

The m1.tiny flavor is not good because now it has a hard coded
1 GiB disk limit and the f20 image requires 2 GiB.
Setting the disk size to '0' -> automatically use the virtual size
of the image.

Using multiple cores does not really helps in boot time :(,
but it might cause higher host load. (More locking)
Reducing the core number to 1.

Change-Id: Ice7c1253d15e91fd1c02bc8c6809335aaebfff4a
Merge "Reserve Keystone ports from the ephemeral range"
Merge "Support option for Keystone PKIZ token provider"
Merge "Cut the heat flavor"
Merge commit 'refs/changes/83/86083/2' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch