Include Test Source folders when gathering unused dependencies

Currently if there are only test folders all dependencies are considered
unused. While this is technically correct, the usage of test-fragments
often is used to import additional requirements, so it seem more safe to
not remove them.

Author: laeubi

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/search/dependencies/GatherUnusedDependenciesOperation.java

@@ -86,7 +86,7 @@ public void run(IProgressMonitor monitor) throws InvocationTargetException, Inte
 			return;
 		}
 		Set<String> computedPackages;
-		try (PdeProjectAnalyzer analyzer = new PdeProjectAnalyzer(fModel.getUnderlyingResource().getProject(), false)) {
+		try (PdeProjectAnalyzer analyzer = new PdeProjectAnalyzer(fModel.getUnderlyingResource().getProject(), true)) {
 			analyzer.setImportPackage("*"); //$NON-NLS-1$
 			analyzer.calcManifest();
 			Packages imports = analyzer.getImports();