Shaders: Set vert shaders to mediump by default.

Seeing errors in logs about precision not agreeing.

assets/shaders/4xhqglsl.vsh

@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;
 uniform vec2 u_texelDelta;

assets/shaders/5xBR.vsh

@@ -18,6 +18,12 @@
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
    
 */
+
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;
 varying vec2 v_texcoord0;

assets/shaders/aacolor.vsh

@@ -1,6 +1,11 @@
 // by guest(r) - guest.r@gmail.com
 // license: GNU-GPL
 
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;
 uniform vec2 u_texelDelta;

assets/shaders/cartoon.vsh

@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;
 uniform vec2 u_texelDelta;

assets/shaders/fxaa.vsh

@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;
 varying vec2 v_texcoord0;

assets/shaders/natural.vsh

@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 uniform vec2 u_texelDelta;
 
 attribute vec4 a_position;

assets/shaders/naturalA.vsh

@@ -1,10 +1,15 @@
-attribute vec4 a_position;
-attribute vec2 a_texcoord0;
-
-varying vec2 v_texcoord0;
-
-void main()
-{
-  gl_Position=a_position;
-  v_texcoord0=a_texcoord0;
-}
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
+attribute vec4 a_position;
+attribute vec2 a_texcoord0;
+
+varying vec2 v_texcoord0;
+
+void main()
+{
+  gl_Position=a_position;
+  v_texcoord0=a_texcoord0;
+}

assets/shaders/upscale_spline36.vsh

@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision mediump float;
+precision mediump int;
+#endif
+
 attribute vec4 a_position;
 attribute vec2 a_texcoord0;