Created and fully implemented a Cross (X) for the game
TicTacApp/CrossEntity.h
TicTacApp/CrossEntity.cpp
  - Create CrossEntity
  - Renders to screen correctly
Modified CircleEntity class slightly

TicTacApp/CircleEntity.h
  - Moved away from namespace DAN
  - Removed getX()
  - Declared setOutlineColor(), setOutlineThickness(), getOutlineThickness()
TicTacApp/CircleEntity.cpp
  - Moved away from namespace DAN
  - Defined setOutlineColor(), setOutlineThickness(), getOutlineThickness()
Changed the size of the window
Updated BoardEntity to hold game logic, place items in specific places

TicTacApp/BoardEntity.h
  - Added constants related to game logic
  - Added place() methods for CircleEntity and CrossEntity
  - Added int[] to represent on screen display of entities

TicTacApp/BoardEntity.cpp
  - Defined both place() methods [uses geometric intersection]
  - Defined winner() to determine when game is over
  - Changed board to use 9 rectangle shapes, one for each empty space
    instead of 4 for lines. Better looking board.
Added method to update game logic

include/App.h
  - Declared and defined empty update() method
src/App.cpp
  - Added a call to update() in loop() after polling for events
Updated TicTacApp to run whole game, but does not display winner

TicTac/TicTacApp.h
  - Added flag m_done for when game is done
  - Added int to indicate whose turn it was
  - Overrode virtual update() method
  - renamed board to m_board
TicTac/TicTacApp.cpp
  - onMousePress() now switches between player turns and
    places the correct pieces on the board
  - update() correctly determines when the game is over and stops
    updates on the board
These items were moved to TicTac since they are specific to TicTacApp