tests/test-debugindexdot.out

record: removed 'has_key' usage

Py3k has removed the dictionary has_key method. This patch implements
a one argument function that can be used as a callback by hg.revert in
the record extension.

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