New Features:
  -Ball is responsive to window size
  -Walls have 3 surfaces - surface and game_init updates
  -Paddle tap now increases ball speed
  -TODO: Add logic for collisions for fast ball with multiple collides

Updates:
  -reorganized pong_game into three components: init, loop, and interface components
  -improved collisions by adding multiple collision checks
  -fixes for ball collide callback
  -collision detection improved for fast moving ball
  -improved behavior consistence
  -drawing data / DOM and object data separation
  -added time error values  TODO: must implement frame rate corrections
  -collision boxes concept added for moving objects
  -improved drawing functions
  -class naming style changes
  -defined vector, movable, surface, and collision classes
  -revised render logic
  -simplified main components
  -UI and interactive events registered in main initialization

Code refactoring:
  -erasion of redundant code
  -comments edit (+6 squashed commits)
  -setInterval is changed to setTimout
  -timing adjustment was removed
  -code from file pong_game.js is now shared between 3 files: pong_game.js, pong_game_init.js, pong_game_loop.js

Bug fixes:
  -game unload and pointer fixes (+1 squashed commit)