Preparatory move for adopting pre-commit hooks.
Shoudl only remove newlines and spaces at end of files.

Change-Id: Ia33679467c533722b9308f7e7b74be395c926428
Signed-off-by: Sorin Sbarnea <ssbarnea@redhat.com>

This commit intentionally introduces a number of important API
breakages. Specifically, the jenkins_jobs.cmd module has been pared
down to some of its most difficult-to-refactor elements.

* Create jenkins_jobs.cli.entry.JenkinsJobs class to organize command
  line parsing and execution.
* Remove references to ConfigParser object in test code, hidden as an
  implementation detail of JenkinsJobs command line parsing. This will
  be necessary in the next stage of JJB 2.0 code which will be to
  create a JJBConfig object that handles logic and presentation of
  configuration from various sources--defaults, command line
  arguments, configuration file, and maybe environment variables in
  the future.
* Remove references to Namespace object produced by argparse module.
  Required rewrite of multipath & recursive path tests with a new
  MatchesDir testtools Matcher class that validates the expected
  output for a run of JJB against a given set of yamldirs with the
  specified command line arguments.
* Use stevedore to dynamically load subcommand parsers.
* Move configuration loading/testing to its own test file. Also fix
  the global vs home directory JJB config file test.

Change-Id: If62280418ba7319c313033ab387af4284237747e