Build with -Wfloat-conversion + fix all warnings

test/testgles2.c

@@ -498,7 +498,7 @@ Render(unsigned int width, unsigned int height, shader_data *data)
     multiply_matrix(matrix_rotate, matrix_modelview, matrix_modelview);
 
     /* Pull the camera back from the cube */
-    matrix_modelview[14] -= 2.5;
+    matrix_modelview[14] -= 2.5f;
 
     perspective_matrix(45.0f, (float)width / height, 0.01f, 100.0f, matrix_perspective);
     multiply_matrix(matrix_perspective, matrix_modelview, matrix_mvp);