Minor tweaks to simplify examples and documentation

##### Issue Type:

Feature Pull Request

##### Ansible Version:

Based on:
ansible 1.5 (devel a0f91f2aaa) last updated 2014/02/05 20:43:12 (GMT +1000)

##### Environment:

N/A

##### Summary:

This is for the improvements I mentioned in #5256

Made a few things more consistent with the bulk of the other EC2
modules and removed an unnecessary check that is handled by
AnsibleModule.

##### Steps To Reproduce:

N/A

##### Expected Results:

No actual change in functionality

##### Actual Results:

No apparent actual change in functionality of the modules I've tested