functions in nested objects are not bound to that object, resulting in inconsistent behavior

Given the following input:
``` javascript
const context = {
nested: {
awesome: function () {
return this.more;
},
more: 'Deeply awesome'
},
more: 'More awesome'
}
```

the following template:
``` handlebars
{{nested.awesome}}
```
yields `'More awesome'`, whereas the equivalent Javascript:

``` javascript
context.nested.awesome()
```
yields `'Deeply awesome'`

More importantly,

```
{{#with nested}}
{{awesome}}
{{/with}}
```
also yields `'Deeply awesome'`.

Here is the [js-fiddle demonstrating this](https://jsfiddle.net/02rxztk5/)

PR submitted with a failing test case: #1861.

Start with the nested-object examples in the issue and the failing test case submitted in PR #1861. Reproduce the difference between {{nested.awesome}} and the #with form, then confirm that direct property access binds the function to the nested object and returns 'Deeply awesome'.

Written by the indexing model from the issue text.