I wrote a [script](https://github.com/j0lv3r4/dependency-version-updater) to update dependencies recursively in `package.json` files, e.g.:
```
$ node index.js --path="./examples" --dependencies="react=^16.7.0,react-dom=^16.7.0"
```
This PR contains the result against the examples folder.
The mobx-state-tree examples (with and without typescript) pre-dated the next _app class and needed to be updated to use _app for persisting state across client-side navigation transitions. Also removed unneeded custom server class to better keep with the "show one feature per example" style of the next examples folder
* Adapt with-mobx example for with-mobx-state-tree
* Remove unnecessary lastUpdate parameter to show off snapshot
* update readme
* make other.js more closely mimic index.js
