Removed PEER, Fixed #183, and more.

```bash
$ grep 'peer' * -rin | wc -l
       0
```

 - Removed all peer stuff. …
 - Adjusted documentation, .xml etc.
 - Abstracted connection handling, so we don't deal with PDOStatement directly anymore, but with DataFetcher, which hides the adapter specific stuff. (PDOStatement etc.)
 - Abstracted OM build process, so the platform can overwrite which OM Build class we use. (`getBuilderClass()`)
 - Made populateObjects name-indexed compatible.

Fixed #183