chcp_beforeInstall event

[toostn]

I've implemented and tested this for iOS. Event is triggered correctly, and I can use it for showing the splash screen as desired in #100.

For Android, maybe the easiest way to fix this is to trigger the event before the InstallationWorker runs?

[nikDemyankov]

Thanks!
As I said before - Android is implemented in a very similar way, as iOS. So yes, probably just need to dispatch the event either in UpdatesInstaller or InstallationWorker.

[toostn]

I've added my attempt of an Android implementation. This works well for my use case and doesn't seem to interfere with anything else, but please check it before merging :)

Since I don't know if the EventBus is thread safe, I added the event trigger outside of the InstallationWorker thread, right before the worker is executed. Feel free to move it wherever you see it fits.

[nikDemyankov]

Awesome, thanks! Seems to be fine. I will merge it in branch dev/v1.3.0, since it's a new feature.

[nikDemyankov]

Merged in branch dev/v1.3.0 with minor bugfix.