RCR 313: rjust, ljust, center split on seperator

Add some additional flexibitiy to String methods rjust, ljust and center.

Just noticed that I had to write my own methods to align each line of a string left, right or center, since rjust, ljust and center only do so for the whole of a string with no regard for line separation.

Generalize the methods adding a separator parameter.

Just seems like a logicial extension of the methods already there, rather then wasting namespace with addtional methods that do almost the same thing.

A minor incompatability arises if the deault seperator is "\n" as I think it likely would best be. Also perhpas the seperator parameter should come before the buffer string parameter.

(P.S. If otherwise rejected what would should the corresponding methods be called?)

Example:

  alias_method :rjust_whole, :rjust
  def rjust(n,c=' ',sep="\n")
    return rjust_whole(n,c) unless sep
    q = split(sep.to_s).collect { |line|
      line.rjust_whole(n,c)
    }
    q.join(sep.to_s)
  end