Set up tool chain to install LO artifacts in Maven repositories

Add <path_to_libo>/bin to your path.
After full LO compile, the LO Java artifacts can be installed in the local
Maven repository:

mvn.py -a install -v 4.2.0 -s juh:jar:<path_to>/juh.jar
mvn.py -a install -v 4.2.0 -s jurt:jar:<path_to>/jurt.jar
mvn.py -a install -v 4.2.0 -s ridl:jar:<path_to>/ridl.jar
mvn.py -a install -v 4.2.0 -s unoil:jar:<path_to>/unoil.jar

With the artifacts installed this way, it is now possible
to consume LO artifacts from custom pom.xml:

[...]
  <properties>
    <LibreOffice-Version>4.2.0</LibreOffice-Version>
  </properties>
[...]
  <dependencies>
    <dependency>
      <groupId>org.libreoffice</groupId>
      <artifactId>juh</artifactId>
      <version>${LibreOffice-Version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.libreoffice</groupId>
      <artifactId>jurt</artifactId>
      <version>${LibreOffice-Version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.libreoffice</groupId>
      <artifactId>ridl</artifactId>
      <version>${LibreOffice-Version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.libreoffice</groupId>
      <artifactId>unoil</artifactId>
      <version>${LibreOffice-Version}</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>

Change-Id: I2ad982ae23c78242ed8f1ac4c88c6be424cc7a0d
Reviewed-on: https://gerrit.libreoffice.org/6453
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>