FS#25 - Change sf::PostFx to a more general purpose pixel shader class (sf::Shader)

Updated the PostFx sample, renamed to Shader
Renamed all the static X::CanUseX() functions to X::IsAvailable() to make the API more consistent
Moved .def files from /build/VC200X to /src in CSFML
Minors fixes in CSFML

git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1258 4e206d99-4929-0410-ac5d-dfc041789085

samples/bin/datas/shader/fisheye.sfx

@@ -0,0 +1,13 @@
+uniform sampler2D texture;
+uniform vec2 mouse;
+
+void main()
+{
+	float len = distance(gl_TexCoord[0].xy, mouse) * 7.0;
+
+    vec2 coords = gl_TexCoord[0].xy;
+	if (len < 1.0)
+		coords += (gl_TexCoord[0].xy - mouse) * len;
+
+    gl_FragColor = texture2D(texture, coords) * gl_Color;	
+}