Tear down old code
Add new data to car
Car constructor automatically fetches time_in
Update car's << operator
Rename constants, update their values
Replace occurrences of deque / que with set / lot
Fix car constructor
Add comparison operators for car

to facilitate the storing of cars in a std::set
Update add_car
Make car's << operator const

to facilitate the printing of iterators
Implement print_lot
Cosmetic changes
Capitalize plate numbers