ELB enhancements

* connection draining
* cross AZ load balancing
Adds support for `kern_id` param in ec2_ls module.
Adds RAM disk id support for ec2_lc module.
Adds support for IAM instance profile in ec2_lc module
Adds support for EBS optimized instances in ecl_lc module.
Adds the possibility to attach a public IP address to instances launched into an autoscaling group within a VPC to ec2_lc module.
Adds support for instance monitoring in ec2_lc module.
The correct option is password_file. Fixes #8752
Docs updates to add examples for symbolic modes

Also fixes missing doc fragments missing in template and assemble
Merge branch 'elb-enhancements' of https://github.com/dataxu/ansible into dataxu-elb-enhancements
Add boto support checks for new ec2_elb_lb attribute fields

Also minor fixes like adjusting version_added fields, etc.
Merge branch 'dataxu-elb-enhancements' into devel
Merge pull request #8757 from sivel/issue/8752

ansible-vault: The correct option is password_file. Fixes #8752
Merge branch 'feature/makes-ec2-lc-boto-iso-functional' of https://github.com/botify-labs/ansible into botify-labs-feature/makes-ec2-lc-boto-iso-functional
Merge branch 'botify-labs-feature/makes-ec2-lc-boto-iso-functional' into devel
Stop/remove existing docker container if the specified tag is different

Fixes #8278
Updating CHANGELOG for ec2_lc/_elb_lb module param additions
Atomically move known hosts file into place for paramiko connections

Redo of original patch, which adds an additional check to ensure the
known_hosts file isn't trampled when host_key_checking is disabled.

Fixes #8169
Initial attempt at RDS and RDS2 refactor
Further refactoring on a long journey towards making rds2 work

Added tests