Refreshed sample config files

Also adjusted config generator to work on master. To generate config, run
  tools/with_venv tools/conf/generate_sample.sh

Two files will be created:
etc/savanna/savanna.conf.sample.raw
etc/savanna/savanna.conf.sample-full

The former of them need to be manually changed to become
etc/savanna/savanna.conf.sample
(at least is lacks [plugin:...] sections)

The savanna.conf.sample-full is created by collecting all the configs
in the code except the ones listed in tools/conf/blacklist.txt

The savanna.conf.sample.raw is also created by collecting all the configs,
but only those listed in tools/conf/whitelist.txt are retained.

Change-Id: I56c009fd6ac1402622e1fee34bfabd8231c1ed6c
Merge "Refreshed sample config files"