Fix issue #2796 (AWS describe_dhcp_options request parsing)

Properly initialize @dhcp_options for each dhcpOptionsSet
Merge pull request #2797 from knatsakis/master

Fix issue #2796 (AWS describe_dhcp_options request parsing)
[google] fixes set_tags
The server password (adminPass) should can be set during server creation.
Merge pull request #2801 from erjohnso/google-set-tags

[google] fixes set_tags
The password attribute doesn't like the use of @password
Merge pull request #2802 from maxlinc/rackspace_admin_pass

Rackspace - support setting admin pass during server creation
Merge pull request #2784 from rackspace/changelog

[core] Convert changelog to markdown
[google] fix service_account scopes
Merge pull request #2805 from erjohnso/google-service-accounts

[google|compute] fix service_account scopes