try to reduce memory usage

patch tab in particular #268

src/Assembly/Metro/Controls/PageTemplates/Games/HaloMap.xaml.cs

@@ -1913,6 +1913,12 @@ public void Dispose()
 
 			ExternalTabsClose(tabs, false);
 
+			_stringIdTrie = null;
+
+			_tagEntries.Clear();
+			_allTags.Entries.Clear();
+			_visibleTags.Entries.Clear();
+
 			//check for any viewvalueas dialogs that rely on this cache and close them
 			foreach (Window w in Application.Current.Windows)
 			{

src/Assembly/Metro/Controls/PageTemplates/PatchControl.xaml.cs

@@ -804,10 +804,6 @@ private void btnExtractInfo_Click(object sender, RoutedEventArgs e)
 
 		#endregion
 
-		#region Patch Convertion Functions
-
-		#endregion
-
 		#region Patch Poking Functions
 
 		private Patch currentPatchToPoke;
@@ -1021,5 +1017,14 @@ private void LoadPatchToPoke()
 		#endregion
 
 		// ReSharper restore UnusedMember.Global
+
+		public void Dispose()
+		{
+			if (currentPatch != null && currentPatch.SegmentChanges != null)
+				currentPatch.SegmentChanges.Clear();
+
+			if (currentPatchToPoke != null && currentPatchToPoke.SegmentChanges != null)
+				currentPatchToPoke.SegmentChanges.Clear();
+		}
 	}
 }

src/Assembly/Windows/Home.xaml.cs

@@ -671,6 +671,7 @@ public void AddPatchTabModule(string patchLocation = null)
 				Content = (patchLocation != null) ? new PatchControl(patchLocation) : new PatchControl()
 			};
 			documentManager.Children.Add(newPatchTab);
+			newPatchTab.Closing += PatchControl_Closing;
 			documentManager.SelectedContentIndex = documentManager.IndexOfChild(newPatchTab);
 		}
 
@@ -915,5 +916,13 @@ private void HaloMap_Closing(object sender, CancelEventArgs e)
 
 			mp.Dispose();
 		}
+
+		private void PatchControl_Closing(object sender, CancelEventArgs e)
+		{
+			LayoutDocument ld = (LayoutDocument)sender;
+			PatchControl mp = (PatchControl)ld.Content;
+
+			mp.Dispose();
+		}
 	}
 }