tests/test-debugindexdot.out

bdiff.c: Added support for py3k.

This patch adds support for py3k in bdiff.c. This is accomplished by including
a header file responsible for abstracting the API differences between python 2
and python 3.

created new head
digraph G {
	-1 -> 0
	0 -> 1
	0 -> 2
	2 -> 3
	1 -> 3
}