Plugins refactor

- Replaced CONFIG_<OS-component>_HOST(S) parameters for CONFIG_CONTROLLER_HOST,
  CONFIG_COMPUTE_HOSTS and CONFIG_NETWORK_HOSTS to minimize count of potential
  deployment architecture to maintainable level
- Unified coding style in plugins, PEP8-tized and forced pep8 check on them

Implements: blueprint simplification

Change-Id: I597f209b62d8d0c3709bb446cb33c804509eef9f
Merge "Plugins refactor"