Added support for GLSL 3 shaders (GLSL 3.30 and GLSL ES 3.00).

To use GLSL 3 in a shader, the first line of the shader has to be: #pragma language glsl3

glsl1 is the default language.

Added “glsl3” graphics feature as part of the table returned by love.graphics.getSupported().

Added love.graphics.validateShader(boolean gles, shadercode). It returns a boolean along with an error string if the shader code has errors for its target language and platform (gles or desktop).

Implemented support for Core Profile OpenGL 3.3 in love.graphics.

--HG--
branch : minor

src/modules/graphics/opengl/StreamBuffer.h

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2006-2017 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#pragma once
+
+#include "graphics/StreamBuffer.h"
+
+namespace love
+{
+namespace graphics
+{
+namespace opengl
+{
+
+love::graphics::StreamBuffer *CreateStreamBuffer(BufferType mode, size_t size);
+
+} // opengl
+} // graphics
+} // love