Log API calls, under 'debug' level

To make this work, move the 'no_dry_run' logging to 'info' level, as it's
clearly more important.  Also fix order of nested decorators, to make function
name propagate correctly.
Make logging level configurable
Clean up CLI output

- Write succesful output on stdout rather than stderr

- Add a newline
Clean up format of API call debug line
Don't document logging in handle_client_errors
Don't use {set notation}, for 2.6 compatibility
Add log_level to haas.cfg.example
Merge pull request #223 from gsilvis/logging

Logging