ApiAnalysisApplication should wait until jobs are done

As part of the build probabbly other jobs are sceduled, the
ApiAnalysisApplication should wait for all jobs to complete before
investigate error markers to prevent problems with outdated states.

apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/ApiAnalysisApplication.java

@@ -127,6 +127,11 @@ public Object start(IApplicationContext context) throws Exception {
 			setTargetPlatform(args.tpFile);
 
 			project.build(IncrementalProjectBuilder.FULL_BUILD, new NullProgressMonitor());
+			// wait untill all jobs has finished that might be sceduled as part of the
+			// build...
+			while (!Job.getJobManager().isIdle()) {
+				Thread.yield();
+			}
 			IMarker[] allProblemMarkers = project.findMarkers(IMarker.PROBLEM, true, IResource.DEPTH_INFINITE);
 			Predicate<IMarker> isAPIMarker = marker -> {
 				try {