This commit adds an additioal jar that is shaded and keeps all the
artifacts that are used by default on the server-side unshaded. Users
that need a shaded jar can now use the `shaded` classifyer to pull
the shaded minimized jar in instead. Including the shaded jar in a
downstream project looks like this:
```XML
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<classifier>shaded</classifier>
</dependency>
```