Made it possible to build using maven.

A maven control file (pom.xml) is created.
This is a matter of taste. Since I made this because I was unable to get the ant build to work, I didn't want to do something that would affect the ant build would not be able to verify that I have not destroyed that possibility. If we should decide to drop the ant build possibility entirely, then we could move around the files. Since I am new to the project, I am not sure how this kind of decisions are suggested, made and communicated so I didn't dare take this kind of initiative.