Allow specifying args directly to actions using module: syntax

Makes things like
- name: do complex things with complex module
  complex:
    setting_a: true
    setting_b:
    - foo
    - bar
possible.

Fixes #2228.

lib/ansible/playbook/task.py

@@ -47,6 +47,13 @@ class Task(object):
             if x in utils.plugins.module_finder:
                 if 'action' in ds:
                     raise errors.AnsibleError("multiple actions specified in task %s" % (ds.get('name', ds['action'])))
+                if isinstance(ds[x], dict):
+                    if 'args' in ds:
+                        raise errors.AnsibleError("can't combine args: and a dict for %s: in task %s" % (x, ds.get('name', "%s: %s" % (x, ds[x]))))
+                    ds['args'] = ds[x]
+                    ds[x] = ''
+                elif ds[x] is None:
+                    ds[x] = ''
                 if not isinstance(ds[x], basestring):
                     raise errors.AnsibleError("action specified for task %s has invalid type %s" % (ds.get('name', "%s: %s" % (x, ds[x])), type(ds[x])))
                 ds['action'] = x + " " + ds[x]