v0.1.4 Going Better

This new release of dart_vlc adds & fixes:

• Now Player no longer requires videoWidth & videoHeight to be passed for video playback.
• Video widget now uses the dimensions of the currently playing video.
• For overriding the automatic video dimensions retrieval, videoDimensions argument must be passed while instantiating Player class.
• Video widget no longer asks for playerId argument, but player instead.
• Added videoDimensionStream and videoDimension attributes to Player class to listen to currently playing video dimensions.
• Migrated C++ code to use smart pointers instead of raw pointers.
• Player.dispose no longer causing crash on Windows (#103).
• Added Add fit and alignment properties to Video widget (Thanks to @jnschulze).