Crazy platform specific hacks, I hate you yarcanox

Fixes issue 4223

Change-Id: I97ab4e201567f8a67bd74e16e4209e2ea1338650
Reviewed-on: http://gerrit.dmdirc.com/1371
Reviewed-by: Chris Smith <chris@dmdirc.com>
Automatic-Compile: DMDirc Local Commits <dmdirc@googlemail.com>

src/com/dmdirc/addons/ui_swing/UIUtilities.java

         UIManager.put("SplitPane.dividerSize", (int) PlatformDefaults.
                 getPanelInsets(0).getValue());
         UIManager.put("TreeUI", "javax.swing.plaf.metal.MetalTreeUI");
+        if ("com.sun.java.swing.plaf.gtk.GTKLookAndFeel".equals(UIManager
+                .getLookAndFeel().getClass().getName())) {
+            UIManager.put("TitledBorder.titleColor", UIManager.getColor(
+                    "Label.foreground"));
+        }
         PlatformDefaults.setDefaultRowAlignmentBaseline(false);
     }