Give reasonable error when symlink fails

When a symlink fails because the path already exists and force=no, we should output path in the error message instead of source.
Make file hardlink error message reasonble

When we hard-link a file, and the link path already exists, give the link path in the error message instead of the source
Check module_path permissions when creating ssh_wrapper for git

If the module directory is not writable/executable to the current user
(most likely because of a sudo to a non-root user), the ssh_wrapper
will be created in the default location for mkstemp() calls. To facilitate
the deletion of these new files, a new mechanism for cleaning up files
created by the module was also added.

Fixes #7375
Add a broken test that shows extensions not skipped
Fixed extension filtering in InventoryDirectory
docker: fix targetting images by name
Stackdriver module was in the wrong category, so moving.
Update composer example

Remove unsupported 'install' argument
fixing some typos in the docs of the yum module
slight language change based on feedback from jimi-c
Remove erroneous set of status_code causing a traceback in module uri

Fixes #7416
Pull the link out of the alternatives output when not specified

Fixes #7414
Add missing space between var and delimeter
Reset locale to 'C' if the specified one is invalid

Fixes #7448
Adding the capability to proxy the ssl cert check

The ssl cert check will now respect the http and https proxy
environment settings. The url may also have the username/password
embedded, in which case basic auth will be used to connect to the
proxy server.

Fixes #7413
Default use_proxy to True for fetch_url()

Also added some error handling to the fetch_url() call in the
apt_repository module, so that failures to look up the PPA info
are properly handled.

Fixes #7322
Also set the environment variables when resetting the locale to C
Add example 'Specify grants composed of more than one word' to the mysql_user module.
Don't re-query inventory when trimming failed/dark hosts

Since the filter list contains hosts, passing that back to list_hosts()
in the inventoy causes issues when the hostname is an IPv6 address
(with :'s interpreted as group unions). Since we already have the list
of hosts, we should not need to pass that back through inventory a
second time.

Fixes #7446
Support internal-only ELBs in EC2.