identify: rename 'changed' keyword -> 'dirty' I meant to do this before sending the initial templater support, but forgot. I'm quite surprised that 'dirty' doesn't occur in more user facing contexts, but there are a few, like the help for blackbox. It also more obviously mirrors the '(clean)' state printed by the summary command. I also didn't like that it was just one letter off from {changes} in the {latesttags} sub-keywords, which has a totally different meaning.

--- a/tests/test-merge-default.t	Sat Jun 24 02:39:21 2017 +0900
+++ b/tests/test-merge-default.t	Sun Jun 25 17:46:35 2017 -0400
@@ -54,7 +54,7 @@
    {
     "bookmarks": [],
     "branch": "default",
-    "changed": "+",
+    "dirty": "+",
     "id": "f25cbe84d8b3+2d95304fed5d+",
     "node": "ffffffffffffffffffffffffffffffffffffffff",
     "p1": [{"node": "f25cbe84d8b320e298e7703f18a25a3959518c23", "rev": 4}],