As part of 94f3b9bf the code was changed to support dynamically adding localhost to the inventory. This change introduced an crash when run via ansible-pull

```
Starting ansible-pull at 2014-01-20 23:09:57
Traceback (most recent call last):
  File "/tmp/ansible/bin/ansible", line 157, in <module>
    (runner, results) = cli.run(options, args)
  File "/tmp/ansible/bin/ansible", line 82, in run
    hosts = inventory_manager.list_hosts(pattern)
  File "/tmp/ansible/lib/ansible/inventory/__init__.py", line 372, in list_hosts
    result = [ h.name for h in self.get_hosts(pattern) ]
  File "/tmp/ansible/lib/ansible/inventory/__init__.py", line 136, in get_hosts
    subset = self._get_hosts(self._subset)
  File "/tmp/ansible/lib/ansible/inventory/__init__.py", line 177, in _get_hosts
    that = self.__get_hosts(p)
  File "/tmp/ansible/lib/ansible/inventory/__init__.py", line 198, in __get_hosts
    hpat = self._hosts_in_unenumerated_pattern(name)
  File "/tmp/ansible/lib/ansible/inventory/__init__.py", line 275, in _hosts_in_unenumerated_pattern
    ungrouped.add_host(new_host)
AttributeError: 'NoneType' object has no attribute 'add_host'
```

The root cause is there is no group for the host to be added to. I fixed this case by creating the ungrouped group when it doesn't exist and then adding the host to the newly added group. This fixes the regression for me.

Fix case where there is a ~/.ssh/known_hosts file and the host key is only in /etc/ssh/ssh_known_hosts

When not finding a host in ~/.ssh/known_hosts, the return value is 0 if the host just is not found. We then never check the system host file in /etc. This fixes the code to check /etc on any failure, not just a bad return code.

This reverts commit 6f4bfa2c, reversing
changes made to c91ba3a7.

Proposing fix for Issue #4324; adding support for su

Mark stat module as supporting check_mode

Enable su support in paramkio; disable su support in fireball, local, accelerate, chroot, jail, funcd connection plugins

Fixes for ssh_alt support, adding in references to in_data where appropriate

yum module: Attempt #2 to cause yum to fail on invalid url

Correctly compare values returned by 'sysctl -e -n'

update default EC2 exclude regions -- this should be the best configuration for most users, but some may still want to tweak.

Make synchronize module work better with local transport, fix #5668

fix str format error due to missing '%' in sysctl module

Spiff up the 'Developing Plugins' page

Colon in example failure message causes a YAML compile error

The example failure message was given as - fail: msg="Bailing out: this play requires 'bar'"

The colon in the example causes a YAML compile error, so I am replacing it with a '.'

Add support for Scientific Linux for hostname module

Allow keystring passed to authorized_key to contain blank lines and comments

the sysctl command. Calling sysctl should also not be true by default

hostname module was lacking support for Scientific Linux, this commit adds it.

Pipelining will be disabled by default, since it requires users remove
the 'requiretty' option from the servers sudoers configuration.

quantum_* modules: Neutron name change, keeping backward compatibility