Merge pull request #274 from kresimirfijacko/fix-memory-leaks

src/webgl.js

 	gl.deleteProgram(this.loadingProgram);
 
 	gl.deleteBuffer(this.vertexBuffer);
+
+	gl.getExtension('WEBGL_lose_context').loseContext();
+	this.canvas.remove();
 };
 
 WebGLRenderer.prototype.resize = function(width, height) {