Preventing multiple observers for the same notification

Fixes #963

Fix partial swipe on video in fullscreen shows a black screen

In iOS 11, Apple added a feature to close the Video Player via a swipe gesture. Partial swiping cases viewWillDisappear to be called without viewDidDisappear which cases a black screen.

Link exoplayer with cookies

Use the client we create earlier in the function

Fix spacing

adds resizeMode to poster image

Set contain as the default mode when not specified

Allow setting progressUpdateInterval to work on iOS

Remove obsolete metadata code that shouldn't have been included

Show options as either true or false and include note about default values.

Update Android instructions for using both ExoPlayer and the old Android player

Make ExoPlayer send onEnd when repeat is on

Support repeat on ExoPlayer

Now that we have updated to a newer ExoPlayer, we can use the setRepeatMode that's available from 2.5 on

Upgrade ExoPlayer to 2.7.2

Fixed rate not being respected after seeking

Reset isCompleted flag on source change

 'Event' does not contain a constructor that takes 2 arguments ReactNativeVideo #878 

update README file for App Transport Security Exception configuration instructions