Tidy up various aspects of the build system to agree with M2E more

* Remove files that M2E generates / regenerates on importing projects into Eclipse
* Ignore these files
* If you pull this, you'll have to reimport these projects
* Remove redundant version numbers
* Change output folder to Maven output folder target/classes/

Any problems with importing Maven projects in Eclipse using M2E ?

See : http://stackoverflow.com/questions/17613685/aspectj-maven-plugin-not-covered-by-lifecycle-in-kepler/18439061#18439061