Initial support for network acls
get_all_network_acls now works properly
Removed extraneous comments.
Added support for associating and disassociating network ACLs and
subnets.
Added supoprt for replacing network acl entries.
Now properly populates NetworkAclEntry class with icmp & port range
options.
Removed unnecessary import of NetworkAclEntry.
Synchronize get_all_snapshots() with current version of API
fix for proxy user with dots or hyphens
fix for os.env proxy without port
added some tests for connections behind proxies
Added launch_config's parameter associate_ip_address for VPC
Adding recipe for parallel execution of activities to SWF tutorial.
Support for instance tenancy in create_vpc
Add DHCP options filtering
Merge pull request #1800 from oozie/swf_tut

Adding recipe for parallel execution of activities to SWF tutorial. Fixes #1800.
Unit tests for create_vpc and get_all_dhcp_options
Convert existing VPC tests to AWSMockServiceTestCase, typos
Fix order of docstring args in get_all_dhcp_options
simplify method_for(), fixing collision with auth/_get_region_name
tighten PEP8
Added tests for the changes to MWS in #1374.