Fixed building on Android, added SDL_opengles2.h, removed unnecessary SDL_glesfuncs.h

--HG--
rename : src/video/SDL_glfuncs.h => src/render/opengl/SDL_glfuncs.h

include/SDL_opengles2.h

@@ -0,0 +1,39 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2010 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+/**
+ *  \file SDL_opengles.h
+ *  
+ *  This is a simple file to encapsulate the OpenGL ES 2.0 API headers.
+ */
+
+#ifdef __IPHONEOS__
+#include <OpenGLES/ES2/gl.h>
+#include <OpenGLES/ES2/glext.h>
+#else
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+#endif
+
+#ifndef APIENTRY
+#define APIENTRY
+#endif