Multiple changes:
Quote variable references to avoid wildcard expansion
Use `tput cols`, falling back to $COLUMNS if that fails, falling back to 80 if that fails
    (May still fail if $COLUMNS is set to a non-number)
Fix test for valid $COLS
Use "#" if an argument is an empty string (avoids an infinite loop)
Move "tput cols" out of loop
Print an empty line for an empty argument
Merge pull request #19 from Keith-S-Thompson/yet-more-fixes

Yet more fixes