Verify Ant Task

I noticed that there was no equivalent ant task for the verify plugin so I decided to take a stab at writing one. It works similarly to the maven plugin. Here are a few examples:

To start you need add the cal10n-api and cal10n-ant-task jars to the ant classpath. Then you need to define the ant tasks using a ```taskdef``` element:

```xml
<taskdef resource="ch/qos/cal10n/ant/antlib.xml" classpathref="cal10n-ant-classpath" uri="antlib:ch.qos.cal10n.ant"/>
```
Then you can use the task like this:

```xml
<cal10n:verify classpathref="project-classpath">
    <enumtypes>
        <enumtype>ch.qos.cal10n.ant.testdata.Colors</enumtype>
        <enumtype>ch.qos.cal10n.ant.testdata.DaysOfTheWeek</enumtype>
    </enumtypes>
</cal10n:verify>
```

The classpath provided to the task is the classpath where the enums and resource bundles to check are located.

You can also specify the classpath using the ```<classpath>``` element inside the task. If you only have one enum that you want to test you can use the ```enumtype``` attribute.

I have included a bunch of unit tests that hopefully covers the vast majority of the use cases. The module can also be expanded to add more task as needed.

I am looking for some feedback on this. I am not a maven expert so hopefully I managed to incorporate the changes in relatively cleanly. Please let me know what you think.