Reworking configuration options

Use config tools from Oslo-incubator :

* generate a consistant config file sample:
  etc/climate/climate.conf.sample

* Add a new check in tox env 'pep8' to check out-dated config file sample.

Move specifics options for admin credential in group config 'physical:host'

Factorize by declaring config options in each plugins with available values and
centralizing RESOURCE_TYPE value in plugin's module (one dir per plugin)

Use socket.gethostname() in place of socket.getfqdn() to have
predictable default value for 'host' config in climate.config,
since it's ugly forced in openstack.common.config.generator#L232

Fixes: bug #1271875

Change-Id: Ie54fc98b58b49400360c4fd2ce7d8bb3b75915e2