Show default values in multiplayer textboxes
Suppress unused variable warning in base event_handler
Slightly simplify makefile
Fix -std
More packet handling for server

* Send rejection packets when a client joins after game has started
* When a client joins, start the game and send the initial peel
  (temporary, since there is no player limit/ready funcitonality yet)
* when a client peels either
  * send next peel letters or
  * announce victory and shutdown
Handle more disconnect reasons
Handle more server packets in client

* accept connection
* peel
* game over

Also send packet for peeling
Fix sending inconsistent peel packets to client
Fix incrementing peel number incorrectly in client
Fix sending peel letter to client incorrectly

Also print error on out-of-order peel
Display remaining letters after peel
Switch backwards victory messages
Correct type for victory packets