Fixes a brief spelling error

Fixes a simple spelling mistake that was bugging me when I read the online
docs. Trying to make the docs as great as possible.

Update add_host example in AWS Guide

The add_host module now uses "groups" instead of "groupname" to allow for specifying more than one group.

- fixed issue with previous commit with bad constants vs C ref on become
- added list-tags
- rearranged common options to utils/cli.py
- added generic validate for both vault and become conflicts
- removed dupes and conflicting options

added generic method to check supported become methods for the connection plugin

fixed command line PE options to be the same as in 1.9

Docsite returnval docs

Also fixing some other become-related things

correctly identifies oracle linux

now add_host loads hostvars

Adds integration tests for new ec2_asg features

Add intro to playbook docs using YAML dictionaries

ignore PE methods that are not sudo for checksums