This allows the EC2 inventory plugin to be used with
the same configuration against different EC2 accounts
Profile can be passed using --profile variable or using
EC2_PROFILE environment variable e.g.
```
EC2_PROFILE=prod ansible-playbook -i ec2.py playbook.yml
```
Added documentation on profiles to EC2 dynamic inventory doc
Only tries to use profiles if --profile argument is given
or EC2_PROFILE is set to maintain compatibility will boto < 2.24.
Works around a minor bug in boto where if you try and use
a security token with a profile it fails (boto/boto#2100)
Introduces destination_format and destination_format_tags
to allow the construction of host names based on one or
more ec2 tags and a python format string.
https://github.com/ansible/ansible/issues/10840
before
RDS: `ERROR: Inventory script (ec2.py) had an execution error: Forbidden`
EC2: `ERROR: Inventory script (ec2.py) had an execution error: Error connecting to AWS backend.
You are not authorized to perform this operation.`
after
RDS: `ERROR: Inventory script (ec2.py) had an execution error: ERROR: "Forbidden", while: getting RDS instances`
EC2: `ERROR: Inventory script (ec2.py) had an execution error: ERROR: "Error connecting to AWS backend.
You are not authorized to perform this operation.", while: getting EC2 instances`
renamed plugins to contrib (they are not really plugins)
rewrote README.md to reflect new usage
added new dir to setup.py so it gets copied with installation, in views
of making using inventory scripts easier in teh future
