[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/alert_bg.frag

@@ -0,0 +1,9 @@
+#version 300 es
+
+in  highp vec4 c;
+out highp vec4 color;
+
+void main()
+{
+  color = c;
+}