Added support for tags to the ec2 module

# Example:

* - name: Launch New Server Instances
* local_action: ec2
   * keypair=${grp_name}
   * group=${grp_name}
   * instance_type=${item.instance}
   * image=${item.image}
   * wait=true
   * user_data='{"servertype":"${item.type}","group":"${grp_name}","name":"${item.name}"}'
   * instance_tags='{"Name":"${grp_name}-${item.name}", "GroupType":"${grp_name}-${item.type}", "ServerType":"${item.type}", "Group":"${grp_name}", "Deployment":"${deployment}"}'
* register: instres
* with_items: ${instances}