Ansible: code cleanup and documentation update

Clean Up (code logic is kept unmodified):
* Remove repetition around `ansible.limit` option (merge conflict issue)
* Re-add missing comments from GH-1697 (merge conflict issue)
* Reorder instructions

Documentation for following changes:
* [GH-1697] add more options
* [GH-1979] extra verbosity option
Ansible: Support three available verbosity levels
Ansible Docs: Add beginner warning

Apply the same warning as in Chef or Puppet pages
Merge pull request #2153 from gildegoma/ansible-docs-cleanup-and-vv

provisioners/ansible: Update documentation, Code Cleanup (and Extend Log Verbosity option)