[libgnome-games-support] Prefer GObject-style construction

[Michael Catanzaro <mcatanzaro src gnome org>]

commit b42a2515acf70dc865908d9ef29c4a1af00e166e
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sun Feb 4 17:07:58 2018 -0600

    Prefer GObject-style construction

 games/gridframe.vala       |    2 +-
 games/scores/category.vala |    3 +--
 games/scores/score.vala    |   19 ++++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)
---
diff --git a/games/gridframe.vala b/games/gridframe.vala
index 14c0a93..1580bcf 100644
--- a/games/gridframe.vala
+++ b/games/gridframe.vala
@@ -114,7 +114,7 @@ public class GridFrame : Gtk.Bin
 
     public GridFrame (int width, int height)
     {
-        @set (width, height);
+        Object (width: width, height: height);
     }
 
     public new void @set (int width, int height)
diff --git a/games/scores/category.vala b/games/scores/category.vala
index 4fb0ff6..328b8ee 100644
--- a/games/scores/category.vala
+++ b/games/scores/category.vala
@@ -45,8 +45,7 @@ public class Category : Object
 
     public Category (string key, string name)
     {
-        this.key = key;
-        this.name = name;
+        Object (key: key, name: name);
     }
 }
 
diff --git a/games/scores/score.vala b/games/scores/score.vala
index 692e43a..9dfa269 100644
--- a/games/scores/score.vala
+++ b/games/scores/score.vala
@@ -24,18 +24,27 @@ namespace Scores {
 public class Score : Object
 {
     public long score { get; set; }
-    public string user { get; set; }
 
     /* Although the scores dialog does not currently display the time a
      * score was achieved, it did in the past and it might again in the future.
      */
-    public int64 time { get; set; }
+    private int64 _time;
+    public int64 time
+    {
+        get { return _time; }
+        set { _time = (value == 0 ? new DateTime.now_local ().to_unix () : value); }
+    }
+
+    private string _user;
+    public string user
+    {
+        get { return _user; }
+        set { _user = (value == null ? Environment.get_real_name () : user); }
+    }
 
     public Score (long score, int64 time = 0, string? user = null)
     {
-        this.score = score;
-        this.time = (time == 0 ? new DateTime.now_local ().to_unix () : time);
-        this.user = (user == null ? Environment.get_real_name () : user);
+        Object (score: score, time: time, user: user);
     }
 
     public static bool equals (Score a, Score b)