added xtraitj as Import-Package in the examples bundle
added xtraitj as Import-Package in the examples bundle

Otherwise the swtbot test would fail when running in tycho since it
would not pick up the right dependency and the mwe2 file would show
error markers due to unresolvable xtraitj.XtraitjStandaloneSetup
reference

Change-Id: I40fb8c2c53299c79306c27fadcfc97c88743fe19

LorenzoBettini/xtraitj,LorenzoBettini/xtraitj