add userdata to ec_context

CMakeLists.txt

@@ -1,6 +1,10 @@
 cmake_minimum_required(VERSION 2.8.12)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_LIST_DIR}/cmake/Modules")
-project(SOEM C)
+cmake_policy(SET CMP0048 NEW)
+project(SOEM
+    DESCRIPTION "Simple Open EtherCAT Master"
+    VERSION 1.4.0
+    LANGUAGES C)
 
 if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
   # Default to installing in SOEM source directory

soem/ethercatmain.h

@@ -426,6 +426,9 @@ struct ecx_context
    int            (*EOEhook)(ecx_contextt * context, uint16 slave, void * eoembx);
    /** flag to control legacy automatic state change or manual state change */
    int            manualstatechange;
+   /** userdata, promotes application configuration esp. in EC_VER2 with multiple 
+    * ec_context instances. Note: userdata memory is managed by application, not SOEM */
+   void           *userdata;
 };
 
 #ifdef EC_VER1