[bnd-maven-plugin] Support resource copying from source and unit test locations

Also added extra unit testing for the maven plugin itself.
Also included preferences for Eclipse to based on the ones from
biz.aQute.bnd
Reworked the unit test to used aQute.lib.io.IO instead of Streams
Merge pull request #436 from bosschaert/testdirs

[bnd-maven-plugin] Support resource copying from source and unit test locations