* src/ntbtls.h.in (ntbtls_get_last_alert): New.
* src/libntbtls.def, src/libntbtls.vers: Add it.
* src/visibility.c, src/visibility.h: Add wrapper.
* src/context.h (struct _ntbtls_context_s): Add field last_alert.
* src/protocol.c (_ntbtls_read_record): Store alert.
(_ntbtls_get_last_alert): New.
* src/ntbtls-cli.c (simple_client): Print last alert.