[react-native] capture and report fatals on next launch

[nevir]

Addresses #468, #533, and maybe #489

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When a fatal (global) error is thrown, raven-js now captures it and persists it before calling the original error handler when in production mode (e.g. so the JS error can bubble out and crash the app). Then, when the react native plugin initializes, it checks for a persisted error, and reports it.

Some finer details:

• In development mode, errors are not persisted, and the default error handler is always called. This allows redboxes to pop as expected.
• Any subsequent fatals thrown while raven-js is persisting the first one are ignored (we want to crash ASAP).
• If the error fails to report; it won't be cleared. This provides a very rudimentary retry mechanism (true offline support should be implemented more robustly, IMO).
• I snuck in Raven.addShouldSendCallback so that the react-native plugin doesn't bash over existing configurations
• onInitialize is useful for detecting if an error was previously reported (say, if you want to pop a "we're sorry" alert, or fix up your store)

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This change is

[Sija]

This would be handy as a transport in other environments too (think no internet situations)

[benvinegar]

Sigh, again hesitant to add more API methods – even though I know this solves some serious problems.

We've talked about just merging shouldSendCallback / dataCallback in a major version change (4.0).

[oliviertassinari]

I'm writing a small plugin to solve #279. This API method would be useful.

[SergeyKorochansky]

I also bumped into this issue. Thank you for PR!

[SergeyKorochansky]

@nevir Thanks for PR. I merged your PR in our fork and it works great!

[benvinegar]

@nevir – possible to update this to reflect changes in #636?

[Kerumen]

Ping @nevir, it would be awesome if you could update the PR. Thanks!

[nevir]

Ack, sorry! Will get to this in the new few days

[nevir]

Alright, rebased it off of the latest! PTAL

[Kerumen]

Ping @benvinegar

[benvinegar]

Here goes nothing!

[nevir]

Sweet!

[abc123s]

@nevir
I have a question on the changes in the this commit.

1. In lines 87-104 of plugins/react-native.js, isn't it possible for originalCallback to be undefined, causing the plugin to crash for non-fatal errors?

[blackxored]

@abc123s Indeed, I'm actually having that exact error atm.

[TSMMark]

For the record, #692 addresses @abc123s's issue