[cluttermm] Point: Replace the regularly-generated default constructor.

[Murray Cumming <murrayc src gnome org>]

commit 1cc41f641d5356542a2c6672809db7aef4b5de2b
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Mar 13 11:09:53 2014 +0100

    Point: Replace the regularly-generated default constructor.
    
    Because it creates a null underlying GObject, which is not what
    people would expect, and which is hopefully not necessary.

 clutter/src/types.hg      |    6 +++++-
 tests/test-point-class.cc |    2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/clutter/src/types.hg b/clutter/src/types.hg
index e6f7e97..2ce1e15 100644
--- a/clutter/src/types.hg
+++ b/clutter/src/types.hg
@@ -92,9 +92,13 @@ class Point
 
 public:
 
+  //We do not want the normal generated constructor
+  //because that creates an unusable object.
+  _CUSTOM_DEFAULT_CTOR
+
   /** Constructor.
    */
-  Point(float x, float y);
+  explicit Point(float x = 0, float y = 0);
 
   // This constructor is just here to prevent calls to Point(int, int) being ambiguous 
   // between Point(float, float) and Point(ClutterPoint*, bool).
diff --git a/tests/test-point-class.cc b/tests/test-point-class.cc
index 37dc7ab..fbe341e 100644
--- a/tests/test-point-class.cc
+++ b/tests/test-point-class.cc
@@ -8,7 +8,7 @@ int main(int argc, char** argv)
 
   std::cout << "Creating Clutter::Point with (int) values: 8, 15" << std::endl;
 
-  Clutter::Point point0(0, 0);
+  Clutter::Point point0;
   Clutter::Point point1(8, 15);
 
   std::cout << "Initialisation: point0 = " << point0.get_x() <<