Previously, the function checked only for a single CA root cert, however
some distributions may have multiple certs in a directory. This will now
try any .crt or .pem file contained within several common paths for
each platform.

Fixes #6412

Use same implementation as ssh.py for "is in host file" checks in module code, prevents git module from adding keys more than once.

add module param to Network and sub-classes of Network, so that ansible 1.5.1 changes to LinuxNetwork apply to all Network classes.

Change-Id: I9b89d433b545269d111b3c290b6411aabf58dd24

Update apt module so that environment variables are set correctly since not going through shell.  Very sorry folks, it will be addressed.

* Adds another module utility file which generalizes the
  access of urls via the urllib* libraries.
* Adds a new spec generator for common arguments.
* Makes the user-agent string configurable.

Fixes #6211

Fixes #6331

tags lists are properly uniqued and joined now, also avoids type issues when passed as list/set or strings

Signed-off-by: Brian Coca <briancoca+ansible@gmail.com>

Fixes #6047

  failed: [127.0.0.1] => {"failed": true, "parsed": false}
  invalid output was: Traceback (most recent call last):
    File "/tmp/ansible-tmp-1393950384.39-102240090845592/nova_compute", line 1328, in <module>
      main()
    File "/tmp/ansible-tmp-1393950384.39-102240090845592/nova_compute", line 241, in main
      except exc.Unauthorized, e:
  NameError: global name 'exc' is not defined

This prevents a traceback when the group is empty.
Fixes #6258

Fixes #5305