[coreutils] seq: Add the ability to process escape characters

[William Plusnick]

When I was looking at seq I noticed it did not process escape character in the separator string. This renders it nearly impossible to separate the numbers by tabs in Bash because when you hit the tab key it tries to autofill and doesn't add the tab in directly. A more concrete example of this is:
$ seq -s"\t" 3
1\t2\t3
$ seq -s" <HITS TAB KEY>
DIRECTORY LISTING

How would you feel about me adding a function that will interpret the escape characters? If this is a good idea, would you rather the function manipulate the string inline or place the new string in a new character array and return a pointer?

Thanks,
William

P.S. Sorry for the poor grammar in the previous git log message, I had been working on an English paper all day and the text on my monitor was starting to blend together. :-S