Source code from dependency with classifier cannot be found

If an app depends on a jar with a classifier then the sources cannot be found and you get the (rubbish) disassembler results. E.g.

```
		<dependency>
			<groupId>com.example</groupId>
			<artifactId>mylibrary</artifactId>
			<version>1.0.0-SNAPSHOT</version>
			<classifier>func</classifier>
		</dependency>
```

might have many classes, and source code, but none of them can be browsed.