[client] use cmake to generate renderers/fonts/clipboards headers/code

This is in preperation of cmake options to enable/disable various
functionallity.

client/renderers/EGL/shader/splash_bg.frag

@@ -0,0 +1,13 @@
+#version 300 es
+
+in  highp vec3  pos;
+in  highp float a;
+out highp vec4  color;
+
+uniform sampler2D sampler1;
+
+void main()
+{
+  highp float d = 1.0 - sqrt(pos.x * pos.x + pos.y * pos.y) / 2.0;
+  color = vec4(0.234375 * d, 0.015625f * d, 0.425781f * d, a);
+}