Fixes to the generation of the Maven pom.xml files

[adamretter]

The published Maven pom.xml file for version 1.1.9-96 is missing a required repository to be able to use the artifact with a Maven project.

i.e. https://repo1.maven.org/maven2/com/xmlcalabash/xmlcalabash/1.1.9-96/xmlcalabash-1.1.9-96.pom is missing the section:

<repositories>
    <repository>
        <id>restlet</id>
        <url>http://maven.restlet.org</url>
    </repository>
</repositories>

which is required to resolve it's dependency on: org.restlet.jee:*:2.2.2.

This PR ensures that:

1. The repository is added to the pom.xml before publishing.
2. The install task also generates the correct pom.xml.

[ndw]

I've merged this one in "by hand" because it seemed to have been half completed through some other fix.

[ndw]

@adamretter with these changes, 'gradle uploadArchives' fails. It claims there's some sort of cycle in the component graph.

Before I rip it all out and put it back the way it was...can you see what's wrong?

[adamretter]

@ndw I am afraid that I worked on this quite some time ago. I don't know or use Gradle, so each time I work with it, I have to go and learn it again. So er... nope I have no idea why uploadArchives would fail, sorry.

[ndw]

Please accept my apologies, Adam. The problem was something to do with gradle 2.10. Per some digging in Google, upgrading gradle fixed it.

[adamretter]

@ndw No worries buddy.