Implement -s option
Keep going if a file is not found
Append ':' to printed filenames
Include backslash in terminal characters
Make exit status dependent on a match having been found
Revise manpage accordingly
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.