Add option to remove players and a confirmation dialog for it.

Also makes the following changes:
- Game now stores the whole passing order and dynamically deduces the player order
- Player adapter now uses the players' timerView-properties as view cache instead of a separate cache to allow esier removal of views
- GameFragment.currentPlayer is set to null on game breaks
- The game is paused on all dialog shows
- All DialogFragments now pause the game when shown and call a function on GameFragment to unpause the game on all possible forms of dialog dismissal. This fixes the bug that the game was left paused when the time change dialog was dismissed.
Move the dialog fragments to their own package and DRY some dialog-related code.
Move all turn handling to a nested class in Game.

The idea is:
- A player's pause() and resume() are called only from the turn handler
- GameFragment never manipulates the players directly
- Players have no knowledge of the game or other players

This fixes any potential bugs related to non-coherent states between the fragment, the game and the players.
Add reset game option with a confirmation dialog.

Also DRYs some DialogFragment code by creating a common dialog builder builder.

Resolves #5
renamed subclass DialogFragments to dialogfragment