Merge pull request #195 from nilshartmann/master

XRef3: "Move referenced Artifacts" Action
~ fixed BM-384 Sometimes Artifact Tree is "confused"
Merge remote-tracking branch 'refs/remotes/origin/master'
Bugfix: only return 'default' version if no version could be determined
BM-380: Invalid SWT Thread Access when analysis model is modified not
from UI thread
Use DefaultManifestCreator when exporting PDE Plug-in Projects
Find Packages by self defined matcher