Fix mmld taglib discovery strategy for Ant compatibility

Quote from John Casey on dev list (20 Jun 05):

The short answer is that there is currently a bug in the m2 integration
of marmalade. Last night I figured out that the taglib discovery
strategy used for the Ant compatibility mode is not configured when m2
attempts to execute a marmalade-mojo. This means that the Ant
functionality will never be recognized.

I'm going to try to get a stop-gap fix in place for the next release of
m2 that will fix this shortcoming. Once that's done, you should be able to:

1. declare the ant namespace using <mojo xmlns:ant="ant:ant">

2. add a project dependency on:

<dependency>
<groupId>marmalade</groupId>
<artifactId>marmalade-compat-ant</artifactId>
<version>1.0-alpha-3</version>
</dependency>