have whereused also check the reflog

Since the stash is part of that, it can also find stashed content.

Sponsored-by: Boyd Stephen Smith Jr. on Patreon

doc/todo/git-annex_whereused.mdwn

@@ -40,3 +40,5 @@ considers a key used despite a previous git rev referring to it. Eg:
 > 
 > Or, if it was found in the ref log, take the "HEAD@{n}" from log
 > output, and add ":filename"
+
+[[done]] --[[Joey]]