Summary:
A bunch of different things was changed, but the most important (and need) change is that `UIManager` is now passed in the function as a regular reference, not as a `shared_ptr`. Besides that fact that passing this as `shared_ptr` is simply incorrect (because there is no ownership sharing/transferring here), we need this change because we cannot construct `shared_ptr` from `this` inside `UIManager` class (especially in the constructor).
Besides that:
* `const &` everything (correctness, explicit intention, performance);
* Names were unified with the rest of the code;
* `auto` everything;
* All JSI stuff is now explicitly prefixed with `jsi::`;
* `using` instead of `typedef` (modern C++ syntax);
* Lamdas instead of std::bind (same perfromance, much more clear and flexible);
Reviewed By: mdvacca
Differential Revision: D9835901
fbshipit-source-id: 935be0ae889fe5508ffa9498282c939c816587e1
2a7bb12e84