Fix editing of Implicit Plugin-Dpendencies

Currently editing the Implicit Plugin-Dpendencies only seem to work
randomly (e.g. if one change some other property along with the change).

This now do not refresh the full target (what seem to reset the
underlying model and remove the dirty flag before changes are applied)
but only updates the UI so finally these thing appear in the target
file.

Fixes #451

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/TargetDefinition.java

@@ -819,6 +819,7 @@ public NameVersionDescriptor[] getImplicitDependencies() {
 
 	@Override
 	public void setImplicitDependencies(NameVersionDescriptor[] bundles) {
+		incrementSequenceNumber();
 		if (bundles != null && bundles.length == 0) {
 			bundles = null;
 		}

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/editor/targetdefinition/ImplicitDependenciesSection.java

@@ -217,9 +217,9 @@ protected void handleAdd() {
 			if (currentBundles != null) {
 				allDependencies.addAll(Arrays.asList(currentBundles));
 			}
-			getTarget().setImplicitDependencies(allDependencies.toArray(new NameVersionDescriptor[allDependencies.size()]));
 			markDirty();
-			refresh();
+			getTarget().setImplicitDependencies(allDependencies.toArray(new NameVersionDescriptor[allDependencies.size()]));
+			updateUI();
 		}
 	}
 
@@ -260,26 +260,30 @@ private void handleRemove() {
 					bundles.remove(removeBundle);
 				}
 			}
-			getTarget().setImplicitDependencies(bundles.toArray((new NameVersionDescriptor[bundles.size()])));
 			markDirty();
-			refresh();
+			getTarget().setImplicitDependencies(bundles.toArray((new NameVersionDescriptor[bundles.size()])));
+			updateUI();
 		}
 	}
 
 	private void handleRemoveAll() {
-		getTarget().setImplicitDependencies(null);
 		markDirty();
-		refresh();
+		getTarget().setImplicitDependencies(null);
+		updateUI();
 	}
 
 	@Override
 	public void refresh() {
 		// TODO Try to retain selection during refresh, add and remove operations
+		updateUI();
+		super.refresh();
+	}
+
+	protected void updateUI() {
 		fViewer.setInput(getTarget());
 		fViewer.refresh();
 		updateButtons();
 		updateCount();
-		super.refresh();
 	}
 
 }