Servers config should require available/enabled dirs

Add SUSE support and 2 small fixes

implement test harness

on openSUSE Leap 15.0, the string was systemd.cpython-36

like openSUSE and SLES

to reduce duplication of constants

deploy certificates directly from pillar

Snippets

Allow installation of multiple packages

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

Replace tabs in pillar.example with spaces.

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
                                   ^
```

Allow to use load_module directly

[nginx/users] convert file.present into file.managed with no content

[nginx/users] add makedirs to htpasswd deploy

Touch htpassw for nginx

[README] include nginx.ng.certifcates

Allow to specify a different passenger config file in nginx.ng

Fix for PR #172

Add default value when calling pillar.get on nginx:ng:dhparam

default value if dhparam isn't defined in the pillar.

Allow debug symbols to be included when compiling from source

Add dhparam creation

Add support for FreeBSD

New Feature/Improvement - Added deleted option to be able to remove site files

update README, closes #121

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