🚀 go-pugleaf

One of the error messages that I most hate to see
is ``unterminated string or character constant''.  I guess
(I haven't looked it up) that ANSI C requires that strings
can contain newlines, which makes reasonable error
detection impossible.

But how about adding a warning for strings that do
not end on the same line as they began? It would be
even better if the warning only happened if that line
did not end with a \.  Then we could put a \ on
the eols that occur in strings whether we intend,
and the compiler would catch the places where we flubbed.

Or am I missing an easy way to find the unmatched string
constants in the first place? I suppose it is not too
painful to search for first exactly one " on a line, then exactly
3, then 5; that's what I'm doing now.