Disables default system animation when resizing AVPlayerLayer

Due to the changes made in #77

Not sure if this something you will want – perhaps it could go behind a flag. When animating video size, the default system animation makes the rendered size of the video lag behind the bounds of the react view. This patch disables the default animation, ensuring the video renders at the correct size.

Update for 0.7.1 release

Fix issues that arise due to accessing _player on a queue other than main

Mild clean ups

Fixes #66

Remove Notification Center observers on dealloc

Changes to README

- Call super in removeFromSuperview
- setRate has to come at the end of modifiers
- Switch to requireNativeComponent

Fix inline image in README

Fix 'Invalid number value (NaN) in JSON write' crash

support for absolute path and file:// paths

Add playableDuration property to onProgress event