Release v2.1.2.0-BETA

Changes in this Release:

• b17c5f2 - Add Contribution details to README
• b69e86e - add generated UML diagrams for classes
• 44ed51b - apply xmllint on pom.xml files
• 5da0af3 - add maven target generate-test-sources for plantuml generation
• e93bc9e - Remove inappropriate symbols from old assets directory
• 19989c3 - Rename some magic variables
• 85da3d2 - Merge pull request #85 from Nokkasiili/master
• 31b39e9 - Add specials to tracks
• 094eeb8 - Rename some magic variables
• 9ec7e0e - Merge pull request #86 from Nokkasiili/master
• 0046c0a - Merge pull request #88 from Nokkasiili/trackspecial
• d2faaef - Add support for IPv6
• a67979c - release version 2.1.2.0-BETA