Check for rst2man on posix doc rendering code path

To help for distros that rename the command (ubuntu).
Updated documentation

- Added custom layout with logo and navigation links
- Corrected command sorting
- Updated description
- Normalized case / naming
Update test to reflect latest doc changes
Merge branch 'brendandixon-update-docs' into develop

Closes #277.

* brendandixon-update-docs:
  Update test to reflect latest doc changes
  Updated documentation
Fix failing integ tests from #277

Also updated the usage strings to be consistent with the
`<command> <subcommand>` changes.
Merge branch 'jamesls-rst2man-ubuntu-fix' into develop

Closes #279, fixes #216

* jamesls-rst2man-ubuntu-fix:
  Check for rst2man on posix doc rendering code path
A WIP commit on an event-based error handler.  Needs tests, etc. but would appreciate review of basic approach.
Move s3 concepts dir into examples directory

There was already a test for this, but we run our tests
against a git checkout of the repo.  However, docs/ is
not part of the sdist which explains why it could pass our
tests but fail to show up when people pip install'd the cli.

Fixes #280.
Merge remote-tracking branch 'upstream/develop' into develop
WIP commit.
Add group_name to arguments

Also unify the public attrs that were added in CLIArgs
but not added to the base class.  In general, all public
interfaces need to be defined in the base CLI class to
make it clear what subclasses need to implement.
Add extra test for boolean arg merging
Merge branch 'merge-bools' into develop

* merge-bools:
  Add extra test for boolean arg merging
  Add group_name to arguments
Updating a few integration tests that were looking for specific error output which has changed with new approach.
Add docstring

As per review feedback.
Merge branch 'error-handler' of git://github.com/garnaat/aws-cli into garnaat-error-handler
Add test for list of scalar complex param
Add cloudfront as a preview service
Merge branch 'json-list-docs' into develop

* json-list-docs:
  Add test for list of scalar complex param
Merge branch 'cloudfront-preview' into develop

* cloudfront-preview:
  Add cloudfront as a preview service