Related to 7027dd0, just link to the online user guide.

The incomplete bundled help was removed in 7027dd0

Fixes: 778981

Pinta.Core/Actions/HelpActions.cs

@@ -82,26 +82,7 @@ private void Bugs_Activated (object sender, EventArgs e)
 
 		private void DisplayHelp (object sender, EventArgs e)
 		{
-			if (SystemManager.GetOperatingSystem() == OS.X11)
-			{
-				// Search for help files in the user's preferred language.
-				var help_dir = Path.Combine (SystemManager.GetDataRootDirectory (), "help");
-				var langs = PintaCore.System.GetLanguageNames ();
-
-				foreach (var lang in langs)
-				{
-					string path = Path.Combine (Path.Combine (help_dir, lang), "pinta");
-					if (Directory.Exists (path))
-					{
-						OpenUrl (string.Format ("ghelp://{0}", path));
-						return;
-					}
-				}
-			}
-
-			// TODO - update this link if we make HTML documentation available
-			// online, or install it with Pinta.
-			OpenUrl ("https://pinta-project.com/howto");
+			OpenUrl ("https://pinta-project.com/user-guide");
 		}
 
 		private void Translate_Activated (object sender, EventArgs e)

Pinta.Core/Managers/SystemManager.cs

@@ -146,17 +146,6 @@ public T[] GetExtensions<T> ()
 			return AddinManager.GetExtensionObjects<T> ();
 		}
 
-		/// <summary>
-		/// Return a list of applicable locale names, ordered from most desirable to least desirable.
-		/// </summary>
-		public string[] GetLanguageNames ()
-		{
-			return GLib.Marshaller.NullTermPtrToStringArray (g_get_language_names (), false);
-		}
-
-		[DllImport ("glib-2.0.dll", CallingConvention = CallingConvention.Cdecl)]
-		private static extern IntPtr g_get_language_names ();
-
 		//From Managed.Windows.Forms/XplatUI
 		[DllImport ("libc")]
 		static extern int uname (IntPtr buf);