eo: eo is absolutely necessary by now, can't be disabled any more.

configure.ac

@@ -25,6 +25,9 @@ EFL_API_LEGACY_DEF="#define EFL_NOLEGACY_API_SUPPORT"
 EFL_API_EO_DEF="#define EFL_EO_API_SUPPORT"
 efl_api="both"
 
+#### For the moment the Eo EFL API is not ready you need to explicitely optin.
+EFL_ENABLE_EO_API_SUPPORT
+
 AC_ARG_WITH([api],
    [AC_HELP_STRING([--with-api=@<:@eo/legacy/both@:>@], [Select the EFL API Model @<:@default=both@:>@])],
    [efl_api=${withval}],

m4/efl_eo.m4

@@ -0,0 +1,6 @@
+dnl use: EFL_ENABLE_EO_API_SUPPORT
+AC_DEFUN([EFL_ENABLE_EO_API_SUPPORT],
+[
+  AC_DEFINE([EFL_EO_API_SUPPORT], [1], [Enable access to unstable EFL Eo API])
+])
+

src/lib/efl/Efl_Config.h.in

@@ -7,7 +7,10 @@
  */
 #ifndef EFL_API_OVERRIDE 
 @EFL_API_LEGACY_DEF@
-@EFL_API_EO_DEF@
+/* You can't disable Eo API anymore as EFL use it everywhere internally
+   and we don't want to expose it publicly just yet, so keep it hidden
+   and require an explicit request to get it. */
+/* @EFL_API_EO_DEF@ */
 #endif
 
 #endif