Update errormanager

Make error_handle_t "private".  Update headers.

src/util/errormanager.h

@@ -1,11 +1,15 @@
 /*
- *  errormanager.h
- *
- *  Created on: Aug 25, 2017
- *
- *      Author: Michael E. Tryby
- *              US EPA - ORD/NRMRL
- */
+ ******************************************************************************
+ Project:      OWA EPANET
+ Version:      2.2
+ Module:       util/errormanager.h
+ Description:  Provides a simple interface for managing files
+ Authors:      see AUTHORS
+ Copyright:    see AUTHORS
+ License:      see LICENSE
+ Last Updated: 04/02/2019
+ ******************************************************************************
+*/
 
 #ifndef ERRORMANAGER_H_
 #define ERRORMANAGER_H_
@@ -17,11 +21,8 @@
 extern "C" {
 #endif
 
-
-typedef struct error_s {
-    int error_status;
-	void (*p_msg_lookup)(int, char*, int);
-} error_handle_t;
+// Forward declaration
+typedef struct error_s error_handle_t;
 
 error_handle_t* create_error_manager(void (*p_error_message)(int, char*, int));
 void delete_error_manager(error_handle_t* error_handle);