Problem 3: Reverse the characters in a line.

For each line in a file (on the standard input), reverse
the order of the characters in the line.

There is an unknown, but fairly small (less than ten thousand)
number of lines in the input file.

Each line is guaranteed to be less than 80 characters long.

For example, if the file on stdin consists of exactly two lines:

hello
world!

then the output should be

olleh
!dlrow

on exactly two lines.  The byte count of a correct output for the
example would be 13 (remember that the newlines count as bytes).
The blank lines in the above listing of the explanation are not 
part of the output.  Note that each output line should be left-
justified (e.g., the ! in the example must come out in column 1).

