#2 New Functionality: InputWindow

[NicroHobak]

Implement the InputWindow class.

InputWindow - A specialized TextWindow for echoing input

• Should have a "send" function pointer so input windows can "send" input to a place of the programmer's choosing
• Should accept input character-by-character, or line-by-line
  • Newlines in input should be handled in one of a few ways
    • Clear window contents and "send"
    • Move contents up (or down, depending on orientation) to make room for a new line of input to echo
  • Each character/line added should flag the window as dirty (depending on if character mode or line mode is enabled)