lib/quantum: refactor quantum plugins and third party

As quantum plugin support is coming like floodlight, nvp and nec,
it's worth while to refactor quantum plugin logic so that each plugin can
be modified/enhanced intervening with other quantum plugin.
And new plugin support can be added easily (hopefully) without modifying
core logic.

Change-Id: Ic5ab5b993272fdd3b4e779823323777a845ee681
Use the correct directory for image files in tempest

Change-Id: Ic40065a04b8015333b4cb6844211e9a0afb9d4c1
Fixes nova-compute failing to start on Fedora 18

Fixes bug #1086784
Adds a rule to the policy-kit allowing the stack user to manage libvirt

Change-Id: I6e9c0106c932f5f5f5c5c18ff79ac81a050c4599
Merge "Use the correct directory for image files in tempest"
add numpy to package list, saves lots of time

websockify was added to the pip requires, and it has a dependency
of numpy. Because we didn't specify it in the package list, it was
built from source every time, adding 3 minutes to an average run.

Stop testing whether numpy compiles 100 times a day in CI.

Change-Id: Ic9d9b8135a917deb846911c6b266aec87d05781a
Merge "Fixes nova-compute failing to start on Fedora 18"
Merge "add numpy to package list, saves lots of time"