Extend Silk format to allow no-name node

Please describe a summary of the new feature (in a paragraph):
When generating object dump, no name node output is useful, especially when
traversing collection data. For example, a node tuple A(B(1), C(2))
represented by class Tuple, which extends ArrayList:

class Node 
{
  public int id;
  public String name;
}

class Tuple extends ArrayList<Node> {
  public String name;
}

Its Silk output should be as follows:
-name:A
-(id:1, name:B)
-(id:2, name:C)

If we use # to denote no name nodes, parenthesis representation of its tree
structure is (A #(id:1 name:B) #(id:2 name:C)), in which A and two #s are
siblings.

Please provide any additional information below:

Original issue reported on code.google.com by taroleo on 13 Oct 2009 at 4:58

RawrUniversal / xerial

Extend Silk format to allow no-name node #39