BREAKING CHANGE: all previous `nginx` based configurations must be reviewed;
`nginx.ng` usage must be promoted to `nginx` and any uses of the original
`nginx` will have to be converted.

Squashed from:

* pillar.example: an include was missing a colon
* pillar.example: 2 directives not indented properly
* pillar.example: added the stock log_format
* pillar.example: make log path match map.jinja
* pillar.example: worker_connections value from latest mainline nginx
* pillar.example: fixed other uses of include
* pillar.example: corrected formatting
* pillar.example: corrected log_format
* pillar.example: reset log_format to try another day

With this one can now also write

 - include:
   - file1
   - file2

Rather than only

 - include: file1
 - include: file2

... by providing a pillar string. I developed this for use in
combination with ext_pillar and file_tree to deploy letsencrypt
certificates.

tabs cause salt to trigger a render error because tabs are 'illegal':
```
yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 33, column 32:
            pid: /var/run/nginx.pid\t\t### Directory location must exist
                                   ^
```

Improvement - Disable reload of nginx when enabled=False (previously the nginx was always reloaded if settings.config != None; even with enabled=False)

Build NGINX from source with nginx.ng state with support for passing
compile time flags necessary for installing modules such as more headers
by the openresty project.

* removed override releasever variable use for CentOS

the debian package installs the nginx service just fine, but the extra
fifo->syslog functionality would be nice to have under debian as well.

Fixes #39.