postgres_db CHECKMODE changed status

Make the changed status for postgres_db under CHECKMODE match the
status that would be returned normally.
`file` module: Don't catch `SystemExit`

This fixes issue #5159.
module(apt_key): don't catch `SystemExit`

If we do this, we risk outputting two JSON payloads, which will be
unparsable.
module(nagios): don't catch `SystemExit`

If we do this, we risk outputting two JSON payloads, which will be
unparsable.
`env-setup` fix for zsh <= 4.3.10

This fixes issue #5026. It used to work. The regression was
introduced in 2b3381de7c6e0924b29123c33f0627a12418f2c8.
Prevent UnicodeEncodeError

Prevents UnicodeEncodeError: 'ascii' codec can't encode character, while printing shell commands output
Avoid UnicodeDecodeError exception when passing module args
Try to follow RFC2812 for waiting on serverl welcome and join messages before performing more tasks
module is not exposed to send_msg, but main() catches exceptions and uses module.fail_json
initial commit of a basic rolling upgrade guide, based on the lamp_haproxy example
flesh out the CI/CD and load balancer sections a bit
tweak some links and phrasing
tests depend on the default encoding being utf8

So we set the utils default encoding to be utf8
improve error on invalid vars file (if its a list instead of a dict)
Fix permission error when using easy_install through sudo

Same as b2542bff72d8b4f5adeec3e0bf6c14c64aaa7e18.
module(file): state what went wrong on exception
module(file): Fail instead of exit on exception
import novaclient.exceptions for cs.images.find

cs.images.find(human_id= throws novaclient.exceptions.NotFound,
resulting in the try/except block with
image = cs.images.find(name=image)  being skipped. catching
novaclient.exception.NotFound allows images to be specified with the
human readable name.

Example:
  tasks:
    - name: Server build request
      local_action:
        module: rax
        region: DFW
        image: Ubuntu 12.04 LTS (Precise Pangolin)

Also, the import is placed after try: import pyrax, because pyrax
imports novaclient and should fail if novaclient is missing.
Adds postgres support for Ansible RDS module
catch exposed cs.exceptions instead of novaclient