Allocates and initializes a new deque.
Deque* deque_create();
Returns: The newly created deque on success, NULL
on failure.
DEQUE_DEFINE_H(IntDeque, int_deque, int)
DEQUE_DEFINE_C(IntDeque, int_deque, int)
IntDeque* deque = int_deque_create();
// Use the deque...
int_deque_free(deque);