otherwise log to syslog

Save loaded plugins list on every plugin install/remove
Load plugins list on startup

Plus jobs subdirectory

This module provide a class representing a loaded plugin, the method
execution job and some helpers.

Added the type in the method signature in cc-common.

Moved some parts to cc-common
Added logging handler for cc-common
Modified binary

Moved to cc-common

Was using a closure for tag function thus storage variable was always
referencing the last value of the iteration.

hypervisor/__init__.py ->
    hypervisor/__init__.py (Handler)
    hypervisor/kvm.py (Hypervisor -> KVM)
    hypervisor/lib.py (Storage*/Volume)