hgweb: rename 'currentbaseline' template keyword to 'basenode'

Shorter and clearer. This keyword represents the node we're currently
diffing against.

mercurial/hgweb/webcommands.py

@@ -293,7 +293,7 b' def changeset(web, req, tmpl):'
                 node=ctx.hex(),
                 parent=webutil.parents(ctx),
                 child=webutil.children(ctx),
-                currentbaseline=basectx.hex(),
+                basenode=basectx.hex(),
                 changesettag=showtags,
                 changesetbookmark=showbookmarks,
                 changesetbranch=showbranch,