support for multiple regions in aws, regions plugin parameter added

regions ec2_eu_west, ec2_us_west, ec2_us_east, ec2_us_west_oregon, ec2_sa_east, ec2_ap_northeast, ec2_ap_southeast, ec2_ap_southeast_2
Merge pull request #1 from andrus7k/patch-1

support for multiple regions in aws, regions plugin parameter added