Implement Parcelable interface
Make class extend support version of Fragment
Make class implement FragmentActivity for support library compatibility
New activity that represents and adventure sheet with all the stats and combats.
Make model classes implement Serializable instead of Parcelable due to circular references in object graph
Small improvements and fixes on AdventureSheetActivity and associated fragments
Start AdventureSheetActivity from other activities
Save stats when their value change in AdventureSheetActivity