Add support for Amazon VPC APIs
Updated all VPC code to move from roboto to requestbuilder backend.
Updated CLI output to match Amazon CLI output.
Updated diff based on gholms comments
Add describe security groups
Merge remote-tracking branch 'rrugge/master' into vpc

Conflicts:
	euca2ools/commands/ec2/createsecuritygroup.py
	euca2ools/commands/ec2/deletesecuritygroup.py
	euca2ools/commands/ec2/describesecuritygroups.py
	euca2ools/commands/euca/associateroutetable.py
	euca2ools/commands/euca/createsecuritygroup.py
	euca2ools/commands/euca/deletesecuritygroup.py
	euca2ools/commands/euca/disassociateroutetable.py
Update DescribeVpcs
Update CreateVpc
Update CreateSubnet
Update DescribeSubnets
Update CreateNetworkAcl and DescribeNetworkAcls
Update CreateNetworkAclEntry
Update DeleteNetworkAclEntry
Update DescribeRouteTables
Update AssociateRouteTable
Add more EC2 resource type prefixes
Update CreateRoute
Update DisassociateRouteTable
Update ReplaceRouteTableAssociation
Update ReplaceRoute