How to loop over this dictionary in Ansible?

Say I have this dictionary

war_files:
  server1:
  - file1.war
  - file2.war
  server2:
  - file1.war
  - file2.war
  - file3.war

and for now I just want to loop over each item (key), and then over each item in the key (value). I did this

- name: Loop over the dictionary
  debug: msg="Key={{ item.key }} value={{ item.value }}"
  with_dict: "{{ war_files }}"

And I get this. It is of course correct, but is NOT what I want.

ok: [localhost] => (item={'value': [u'file1.war', u'file2.war'], 'key': u'server1'}) => {
    "item": {
        "key": "server1", 
        "value": [
            "file1.war", 
            "file2.war"
        ]
    }, 
    "msg": "Server=server1, WAR=[u'file1.war', u'file2.war']"
}
ok: [localhost] => (item={'value': [u'file1.war', u'file2.war', u'file3.war'], 'key': u'server2'}) => {
    "item": {
        "key": "server2", 
        "value": [
            "file1.war", 
            "file2.war", 
            "file3.war"
        ]
    }, 
    "msg": "Server=server2, WAR=[u'file1.war', u'file2.war', u'file3.war']"
}

I want to get an output that says

"msg": "Server=server1, WAR=file1.war"
"msg": "Server=server1, WAR=file2.war"
"msg": "Server=server2, WAR=file1.war"
"msg": "Server=server2, WAR=file2.war"
"msg": "Server=server2, WAR=file3.war"

IOW, how can I write a task to iterates over the dictionary so it goes through each key, and then the items within each key? In essence, I have a nested array and want to iterate over it?

Hows this

- hosts: localhost
  vars:
    war_files:
      server1:
      - file1.war
      - file2.war
      server2:
      - file1.war
      - file2.war
      - file3.war
  tasks:
    - name: Loop over subelements of the dictionary
      debug:
        msg: "Key={{ item.0.key }} value={{ item.1 }}"
      loop: "{{ war_files | dict2items | subelements('value') }}"

dict2items, subelements filters are coming in Ansible 2.6.

FYI, if a filter for your objective doesn't exist, you can write your own in python without having to resort to jinja2 hacks. Ansible is easily extendable; filters in filter_plugins/*.py are searched by default adjacent to your plays/roles and are automatically included - see Developing Plugins for details.

Now Ansible allows this

- name: add several users
  user:
    name: "{{ item.name }}"
    state: present
    groups: "{{ item.groups }}"
  with_items:
    - { name: 'testuser1', groups: 'wheel' }
    - { name: 'testuser2', groups: 'root' }