(byte-compile-display-log-head-p): New

(byte-compile-display-log-head-p): New
function extracted from byte-compile-log-1.
(byte-compile-log-1): Change output to be more in line with
the output of other GNU tools.
(byte-compile-warn): Emit `warning' instead of `**' for warnings.
(byte-compile-report-error): Downcase error message.  Use
`error' instead of `!!' for error messages.
(byte-compile-print-syms): Treat non-interactive case specially.
(displaying-byte-compile-warnings): Use backquote.
(byte-compile-from-buffer): Bind byte-compile-last-line.
(batch-byte-compile): Remove `Done' message.