EC2 inventory toggle to exclude/include RDS instances.
Do not filter out RDS instances by default or in INI file to avoid changing current behaviour.
Merge branch 'ec2inv-rdstoggle' of https://github.com/ingmar/ansible into ingmar-ec2inv-rdstoggle

Conflicts:
	plugins/inventory/ec2.py
Merge branch 'ingmar-ec2inv-rdstoggle' into devel