Update pyrakoon - make it a standalone package

[JeffreyDevloo]

Pyrakoon should be updated and made a standalone package instead of embedding the code in the extensions
Keep in my mind that the extensions library is a dependency of just about any component. Therefore think about compatibility.
All dependent componenets should migrate away from ovs_extensions.db.arakoon.pyrakoon.pyrakoon.compat import ... to from pyrakoon.compat import ...
The first draft can be found here:

Other associated repositories:

• asd-manager
• iscsi-manager
• s3-manager
• Framework: to be implemented