Adding MathML support using JEuclid

By default, the JEuclid library is excluded from the oxygen-sdk artifact dependencies. To enable it, comment the following lines in the pom.xml file:

<exclusion>
    <artifactId>jeuclid-core</artifactId>
    <groupId>net.sourceforge.jeuclid</groupId>
</exclusion>

To edit specialized DITA Composite with MathML content, include the entire [OXYGEN_DIR]/frameworks/mathml2 Mathml2 framework directory in the frameworks bundled with the component in the bundle-frameworks module. This directory is used to solve references to MathML DTDs.