Add module support for Rackspace Cloud Files Containers

Module support for Rackspace Cloud Files

rax_dns_record: Add rax_dns_record module

Fix bug where playbook tasks do not escalate privs with 'su'

Add rax_dns module

Disallow su and sudo params in same play/task

Adding a check for pending tranasctions to the yum module

Fixes #4649

Bug in constants.py, ANSIBLE_SSH_PIPELINING should be coerced to boolean

Bug: chmod should be called only if the tmp dir was created in the first...

Add su support

rax module: Fix regex match

module unarchive: documentation typos

notify/grove: set the service to "ansible" by default

digital_ocean: added requirements in DOCUMENTATION

Fix an issue where ansbile-pull fails with AttributeError

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 c17d0e03.

Conflicts:
	lib/ansible/runner/connection_plugins/paramiko_ssh.py

This reduces the number of times inventory.list_hosts is called, which
can be costly. When coming from a playbook that data is already known.

Operate on that play attribute to make things faster for larger
inventories. Instead of making a round trip through inventory.list_hosts
and working through some lengthy list comprehensions over and over
again, calculate the potenital hosts for a play once, then reduce from
it the unavailable hosts when necessary.

Also moves how the %fail is done. The host count is a play level count
of available hosts, which then is compared after each task to the
current number of available hosts for the play. This used to get a new
count every task which was also time expensive.

Fix regex match, the printf match should work with 0 or more numeric padding characters, not 1 or more

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