0.0.34

Feature/memory player (#134)

* Memory player implementation

* Added factories for DataSource

* Refactored data sources

* Fixed placeholder showing after full screen when using showPlaceholderUntilPlay

* Added setControlsVisibility to BetterPlayerController

* Removed showControlsOnInitialize from BetterPlayerConfiguration

* Fixed cupertino controls issue with hasError

* Dartfmt