Bug 470063 - [GTK] Child shells cannot be unminimized

Adds a taskbar icon for minimizable child shells, enabling them to be
directly unminimized.

Change-Id: I752c29a2a3595fad94379ff3a6538ede709bab70
Signed-off-by: Alexandra Buzila <abuzila@eclipsesource.com>
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
index 43475a3..3cb521b 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
@@ -697,7 +697,11 @@
 		if (parent != null) {
 			OS.gtk_window_set_transient_for (shellHandle, parent.topHandle ());
 			OS.gtk_window_set_destroy_with_parent (shellHandle, true);
-			OS.gtk_window_set_skip_taskbar_hint(shellHandle, true);
+			// if child shells are minimizable, we want them to have a
+			// taskbar icon, so they can be unminimized
+			if ((style & SWT.MIN) == 0) {
+				OS.gtk_window_set_skip_taskbar_hint(shellHandle, true);
+			}
 
 			/*
 			 * For systems running Metacity, by applying the dialog type hint