cleanup and simplify

releng.wtpbuilder/distribution/wtp.tests/tobeInstalled.properties

 getprereq.eclipse=true
 getprereq.eclipsetestframework=true
 #getprereq.eclipseplatform=false
-getprereq.emf=false
-getprereq.emfxsd=false
+getprereq.emf=true
+getprereq.emfxsd=true
 #getprereq.emfvalidation=false
-getprereq.gef=false
-getprereq.dtp=false
+getprereq.gef=true
+getprereq.dtp=true
 #getprereq.wst=false
 #getprereq.jst=false
-getprereq.wtp=false
+getprereq.wtp=true
 #getprereq.dltk=false
-
+getprereq.wtp-tests=true
 getprereq.testlibraries=true