added all basic elements
players have units and nodes
a creep is added for every player as a part of board creation
units now have a player attribute
players use a turnRank attribute to get their creeps from the board

Since neither the player nor the board has access to the players list, they have to use a shared stat so the player can get its information from the board.

The turn rank will have to be modified if players are eliminated from the game, which isn't possible now.
Nodes now also have a player attribute
Fixed bug related to playerNodes by making all void initialized nodes have a player value of -1.

This can be leveraged later to identify which nodes are player or computer controlled.

Also, added occupied identifiers to nodes
units have their own print method
CreepNodes have a print function
Merge branch 'f-conversation' into develop