new file:   cell.cpp
	new file:   cell.h
            can handle (+ 1 2) expression.
add car, cdr, cons operator
add read_from, make_list for parsing input string
fixed for new Cell
fixed for compiling
add get_cell(ProcType proc) for primitive proc
add some function declare
add s32_itoa_s(), fixed some function prototype for Cell => Cell*
modify for cell.h cell.cpp
kind_str() => type_str()

Cell *get_cell(ProcType proc); => Cell *get_cell(const char *val, ProcType proc);
modify:
  eval
  list_of_values
  apply
  proc_add

  for evaluate (+ 1 2)
modify print format
add proc_mul()
remove orginal eval()
modify lookup_variable_value
add proc_sub()
add is_list(), length_cell() but not complete
add lambda_ for lambda expression. cons_cell(): check 0 pointer
fixed for lambda expression