Suppress dumping of whole configuratinos by default
Added `--dump-config-as-info` option to allow users to dump config at the log level INFO.
Changed config dump strategy

  * default: dump config as it does till now
  * option: `--suppress-config-dump` as optional command line flag
Merge pull request #186 from kentaro/suppress-config-dumping

Suppress dumping of whole configuratinos by default