Add "--with-id" configure option that can be used to specify a

string identifying the build (vendor, maintainer, etc). It defines
EFL_BUILD_ID with default to "none". It can be used by applications
or for bug reports by including Efl_Config.h

Differential Revision: https://phab.enlightenment.org/D288

configure.ac

@@ -55,6 +55,16 @@ AC_SUBST(EFL_API_EO_DEF)
 
 #### Additional options to configure
 
+# string to identify the build
+AC_ARG_WITH([id],
+   [AC_HELP_STRING([--with-id=BUILD_ID],
+                   [Specify a string to identify the build (vendor, maintainer, etc).
+                     @<:@default=none@:>@])],
+   [EFL_BUILD_ID="${withval}"],
+   [EFL_BUILD_ID="none"])
+AC_SUBST(EFL_BUILD_ID)
+
+# profile
 AC_ARG_WITH([profile],
    [AC_HELP_STRING([--with-profile=PROFILE],
                    [use the predefined build profile, one of: dev, debug and release.

src/lib/efl/Efl_Config.h.in

@@ -15,5 +15,6 @@
 
 #define EFL_VERSION_MAJOR @EFL_VERSION_MAJOR@
 #define EFL_VERSION_MINOR @EFL_VERSION_MINOR@
+#define EFL_BUILD_ID "@EFL_BUILD_ID@"
 
 #endif