Move everything from global namespace to "sp" namespace

When writing the X11 (linux) implementation there was a problem with X11 defining a "Display" type and we also have a Display class in the engine.

So to fix that problem and minimize the risk for running into other name conflicts. We move everything from global namespace.

include/Spectre/Scene/Camera2D.h

@@ -13,6 +13,8 @@
 // TODO: Zoom is implemented using a scale matrix. 
 // It's abit weird to control. Must be a better solution.
 
+namespace sp {
+
 class Camera2D : public ICamera
 {
 public :
@@ -29,7 +31,7 @@ public :
 
 	void move(float x, float y);
 	void move(const Vector2f& vec);
-	
+
 	void moveUp(float delta);
 	void moveRight(float delta);
 
@@ -80,4 +82,6 @@ protected :
 	mutable bool		m_projViewNeedsUpdate;
 };
 
+} // namespace sp
+
 #endif /* SPECTRE_SCENE_CAMERA2D_H */

include/Spectre/Scene/ICamera.h

@@ -4,6 +4,8 @@
 
 #include <Spectre/Math/Matrix4.h>
 
+namespace sp {
+
 // Camera interface.
 class ICamera
 {
@@ -17,4 +19,6 @@ public :
 	virtual const Matrix4f& getProjectionViewMatrix() const = 0;
 };
 
+} // namespace sp
+
 #endif /* SPECTRE_SCENE_ICAMERA_H */