Adding support for SSL-Certificates per Domain

> [Milestone 0.9.29]
Comments and Feedback can be left at [byteworkshosting issue #6] (https://github.com/byteworkshosting/Froxlor/issues/6 "Adding support for SSL-Certificates per Domain") .

## NOT READY FOR MERGE!

This update adds support for `SSL-Certificate per Domain`.
*(Fully supported only with Nginx-Webserver until now)*

```
Caution: Be aware that this is a alpha release!
```

- - -
* [Issue #261] (http://redmine.froxlor.org/issues/261 "SSL Verwaltung")
* [Issue #365] (http://redmine.froxlor.org/issues/365 "SSL certificates should be settable per domain")