made nested lists diff lengths - caused confusion

As a relatively-new user to Ansible, the Nested Loop example made me think it was looping through both lists together (`alice` would go with `clientdb`, `bob` with `employeedb`) and not actually nested. I realize now I was just being stupid, but I feel making the example lists different lengths would prevent such confusion in the future.
Fix order of merging variables for the combined cache

Fixes #7598
Merge branch 'rax-meta' of https://github.com/sivel/ansible into sivel-rax-meta
Adding the new rax_meta module to the CHANGELOG
Merge branch 'sivel-rax-meta' into devel
Merge pull request #7656 from tsemerad/patch-1

made nested lists diff lengths - caused confusion
Tweaking make_su_cmd test

Fixes #7652
Fix error passing play vars to an included playbook with empty vars

Fixes #7658
Clarified, remote_user config item does override ansible current user if defined.
Merge pull request #7662 from billcarlson/devel

Clarified, remote_user config item does override ansible current user
Fixing version_added strings for new features in ec2_elb_lb

Fixes #7631
Add additional params to get_target_from_rule method in ec2_group

Fixes #7592
Add rackconnect and managed cloud automation check examples
Add support for relative paths in the file lookup plugin for roles

Fixes #7628
ansible-pull should respect inventory file settings because, say, Python interpreter path can be non-default on a host
Fix linking issue to directories in file module

The os.path.isdir() returns True for symlinks that point to directories,
so we also need to check to make sure it's not a symlink too.

Fixes #7657
Fix issue with symlink path detection

Fixes #7627
Fixes #7664
Merge pull request #7667 from alexclear/devel

ansible-pull should respect inventory file settings because, say, Python...
Added cross-platform uptime fact

Having an uptime fact allows you to check after a reboot whether the system was effectively rebooted.

```yaml
  - name: Safeguard - Was system properly rebooted ?
    action: fail msg="System was not properly rebooted"
    when: ansible_uptime > 900
```

This patch has been tested on Linux, Solaris and HP-UX.
Update facts.py