Fixed problem with non-synchronous error lists

in perror and handler descriptors (BUG#25177)
Fixed problem of masking mysql error by system
  error in perror (BUG#23028)


extra/perror.c:
  Used common handlers error list.
  Fixed BUG#23028 ignoring mysql error in case of
  OS and mysql error codes overlapping.
include/my_base.h:
  Added errors of maria engine.
  Fixed incorrect comment in #define (can be cause of
  seriouse problems)
include/my_handler.h:
  Added ability to be included into C++ code.
mysys/my_handler.c:
  Error texts moved to the separate files.
mysys/my_handler_errors.h:
  New BitKeeper file ``mysys/my_handler_errors.h''

include/my_handler.h

@@ -19,6 +19,9 @@
 #define _my_handler_h
 
 #include "myisampack.h"
+#ifdef	__cplusplus
+extern "C" {
+#endif
 
 /*
   There is a hard limit for the maximum number of keys as there are only
@@ -118,5 +121,8 @@ extern void my_handler_error_unregister(void);
   this amount of bytes.
 */
 #define portable_sizeof_char_ptr 8
+#ifdef	__cplusplus
+}
+#endif
 
 #endif /* _my_handler_h */