[gnome-mines] Do not create new fundamental types

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 8adf48796dee876c4253045180eba4863f075676
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Jun 24 08:43:25 2014 -0500

    Do not create new fundamental types
    
    Avoid potential odd bugs like
    https://bugzilla.gnome.org/show_bug.cgi?id=708130#c21

 src/history.vala   |    4 ++--
 src/minefield.vala |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/history.vala b/src/history.vala
index 8229610..d9174ec 100644
--- a/src/history.vala
+++ b/src/history.vala
@@ -8,7 +8,7 @@
  * license.
  */
 
-public class History
+public class History : Object
 {
     public string filename;
     public List<HistoryEntry> entries;
@@ -99,7 +99,7 @@ public class History
     }
 }
 
-public class HistoryEntry
+public class HistoryEntry : Object
 {
     public DateTime date;
     public uint width;
diff --git a/src/minefield.vala b/src/minefield.vala
index 1fb0fbb..d9416e0 100644
--- a/src/minefield.vala
+++ b/src/minefield.vala
@@ -15,7 +15,7 @@ public enum FlagType
     MAYBE
 }
 
-private class Location
+private class Location : Object
 {
     /* true if contains a mine */
     public bool has_mine = false;
@@ -45,7 +45,7 @@ private static const Neighbour neighbour_map[] =
     {-1, 0}
 };
 
-public class Minefield
+public class Minefield : Object
 {
     /* Size of map */
     public uint width = 0;