2972

Slightly more lenient function-prototype generation.
2973 - warn noobs who type in 'abc'

Important to ensure we don't seem to hang in Interactive
mode waiting for data for a clearer error message.

But down the road I want to be able to scan recent traces
to give the user context on where the error occurred.
2974 - problems with 2973

peek_next_atom() corrupts its input stream and leaks memory, but
we never noticed because of Count_raises.
2975
2976 - stop corrupting stream after seek
2977 - fix memory leak in 2973
2978 - never hide errors during test verify
2979
2980 - RAISE warnings using trace

Issues like 2974 can't happen anymore.
2981
2982
2983
2984

Make sure that:
  we don't print redundant errors if the test already failed
  we don't print warnings if the test explicitly hid them
  we print errors if there were no warnings to print
2985 - now Num_raises is redundant