When nesting for non-list contexts, inherit list info.

This ensures that if you enter a conditional block while inside a list
block, the list "state" from the outer list will still be visible. For
example (somewhat contrived, but gets the point across):

{{#list}}
{{#name}}{{-index}}. {{.}}{{/name}}
{{^name}}{{-index}}. No name!{{/name}}
{{/list}}

Yields something like:

1. Bob
2. Mary
3. No name!
4. Jim

Fixes #90.

src/main/java/com/samskivert/mustache/Mustache.java

@@ -878,7 +878,7 @@ public class Mustache
             } else if (_comp.isFalsey(value)) {
                 // omit the section
             } else {
-                executeSegs(tmpl, ctx.nest(value, 0, false, false), out);
+                executeSegs(tmpl, ctx.nest(value), out);
             }
         }
         @Override public void decompile (Delims delims, StringBuilder into) {