1.
New commands "p5 bdiff" and "p5 bprint" for examining files in a
previously saved backup.
2. On a syntax error, only print the relevant line of the Usage message
instead of the whole thing.
3. Be less chatty about what commands we're executing to get the job
done ("p4 client" and "p4 opened" in particular). Anyone who really
cares can say "p5 -v COMMAND".