Fix code analytics

This PR ..

* tweaks PMD to properly ignore the protobuf code files and disables the [Logging Guards Warning](http://pmd.sourceforge.net/pmd-5.1.1/rules/java/logging-java.html#GuardLogStatementJavaUtil) which was reported in hundreds of files as "serious problem" - which it isn't imho.
* Fixes all checkstyle errors
* Fixes all but one FindBugs "serious problems"
* Removes the main() method in `ColladaLoader` :smile: 
* Removes WorldRendererLwjgl.toString() which was broken for ages and no one noticed
* Lots of minor issues such as typos and whitespace

See see charts at http://jenkins.terasology.org/job/TerasologyTemp/ to see the effect of this PR.