FEATURE Add NETCONF time function

Add implementation of public functions to work with timestamps in the
NETCONF format.
diff --git a/nc_transapi.h b/nc_transapi.h
index 6ca842b..76de063 100644
--- a/nc_transapi.h
+++ b/nc_transapi.h
@@ -23,6 +23,6 @@
 #ifndef NC_TRANSAPI_H_
 #define NC_TRANSAPI_H_
 
-#include <libnetconf2/log.h>
+#include <nc_server.h>
 
 #endif /* NC_TRANSAPI_H_ */