Add the maven-compiler-plugin directive so that older versions of Maven ...

...don't try and use the 1.3 JDK.

Previous to Maven 3.0, it assumes everything is compatible with Java 1.3. You can fix this by specifying the maven-complier-plugin version later than 3.0 where Java 5 will be used.

http://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html#source

Errors:
```
/data/noit/src/java/reconnoiter-riemann/src/main/java/com/omniti/reconnoiter/EventHandler.java:[61,20] generics are not supported in -source 1.3
(use -source 5 or higher to enable generics)
  private LinkedList<MessageHandler> alternates;

/data/noit/src/java/reconnoiter-riemann/src/main/java/com/omniti/reconnoiter/EventHandler.java:[109,28] for-each loops are not supported in -source 1.3
(use -source 5 or higher to enable for-each loops)
    for ( MessageHandler mh : alternates )
```