help: document that [subpaths] may rewrite relative paths
The subpaths substitution logic first attempts to match the absolute
repository path, then the relative subrepository path if that failed.
--- a/mercurial/help/config.txt Tue Jun 07 08:32:33 2016 +0200
+++ b/mercurial/help/config.txt Thu Jun 16 09:15:12 2016 -0700
@@ -1485,8 +1485,9 @@
rewrites ``http://server/foo-hg/`` into ``http://hg.server/foo/``.
Relative subrepository paths are first made absolute, and the
-rewrite rules are then applied on the full (absolute) path. The rules
-are applied in definition order.
+rewrite rules are then applied on the full (absolute) path. If ``pattern``
+doesn't match the full path, an attempt is made to apply it on the
+relative path alone. The rules are applied in definition order.
``templatealias``
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