Nova Hyper-V driver refactoring

Blueprint: hyper-v-testing-serialization-improvements

This patchset contains a major refactoring of the Hyper-V driver.

The main reason for this refactoring is to provide proper component
abstraction and decoupling, thus replacing almost entirely the remaining
pre-Essex code previously available. This leads to a considerable
semplification of the testing framework, which is now entirely based on
stubs and mocks (mox), without any serialized stub / mock.

From an architectural perspective, the main driver class delegates
operations to "ops" classes (e.g. VMOps, VolumeOps, etc) which contain the
main logic and delegate OS specific actions to "utils" classes (e.g. VMUtils,
LiveMigrationUtils, etc) where the WMI and Win32 API OS specific code resides.

Additional attention has been put also into a better PEP8 code formatting,
including compliance with not mandatory checks like E121 through E128.

Change-Id: I900719c02b7c6b48d44ca68903813a1dcd023f9f
Merge "Nova Hyper-V driver refactoring"