Don't send unicode instances to the selinux module

Showcase the new-style lookup plugin access in the authorized_key docs rather than the old-style $FILE

This fixes #2632.  Briefly: specifying things like paths using complex
args in a playbook will make the objects unicode instances.  The selinux
module does not accept unicode instances for its char * arguments; it
wants str instances.

Per mpdehaan's comment on #2632 I just went ahead and converted all
paths to UTF-8.  I don't know if it would be better to do something like
converting to locale.getpreferredencoding(), but I factored all the
conversions out into new method _to_filesystem_str, so there's only one
place that needs to be changed in the future.

Typo in example, extra space breaks playbook.

Showcase the new-style lookup plugin access in the authorized_key docs rather than the old-style $FILE

Small spelling correction to authorized_key module docs

clean up first_found to fix a few issues:

 - add a skip option so it won't raise an exception if you don't match anything
 - make it work as a drop-in replacement for first_available_file
 - document in the module comments all of the above cases

Revert "make atomic_replace use shutil.copy2 instead of os.rename() so it will work across filesystems".

AR function was leaving some tmp files behind, want to revert, will have better implementation soon, this is the old way now.

This reverts commit f74a1fa4.

correct reference to module

(B) allow registration with ignore_errors: True

Fix if-statement that always evaluates True

Fix 'sequence' plugin error.

If 'terms' is a string, replace it with a single item list.

Fix errors in lookup plugins.

Lookup plugins 'sequence' and 'template' now import 'ansible.utils'
appropriately in order to use the 'listify_lookup_plugin_terms'
function.

Also, 'dnstxt' and 'env' now check to see if 'terms' is a string;
without this calls like '{{ lookup('env', 'HOME') }}' fail.

ec2_facts: add ansible_ec2_placement_region key/value pair for EC2 regio...

The copy action accepts force=no, which tells it not to replace an
existing file even if it differs from the source.  The copy action
plug-in wasn't respecting this option when operated in check mode, so it
would report that changes are necessary in check mode even though copy
would make no changes when run normally.

Runner._remote_md5 was changed to make the logic for setting rc perhaps
a little more clear, and to make sure that rc=0 when the file does not
exist.

Add availability zone parameter

Conflicts:
	lib/ansible/inventory/vars_plugins/group_vars.py
	lib/ansible/runner/__init__.py
	lib/ansible/utils/__init__.py
	test/TestPlayBook.py

Look for a file with the base name of the group/host, first without
a file extension, then with a '.yml' extension, and, finally, with
a '.yaml' extension, loading vars from only the first one found.

Ec2 vol improvements

Minor fixes to the rax module