Container flavor settings and Vswap

* This allows for defining exact vz configs for specific flavor, instead
  of the driver calculating them.  We can define future flavor-specific
  vz configs through nova flavor extra_specs (metadata) instead of adding
  configs in the driver.

  Current vz configs that can be defined through flavor extra specs:
  - 'vz_config_file': vz config file to initially apply
  - 'vz_cpulimit': vz cpulimit
  - 'vz_bandwidth': tc bandwidth limit

* Vswap has been added as the new default way of setting memory settings

* Refactoring has been done to use new Container class.  Also new
  resource_manager class has been created to centralize most vz calculations
  and config logic (vz networking has been left alone).

* Got rid of reset_instance_size since its not used by nova-compute manager.

* Changed vz config that is initially applied to be a fresh new container
  config and flavor extra_specs driven.

Change-Id: I125682bbe89cedec08f328394ebb402a5c079b6d