Added the special method 'new' for classes which will be called when a class is initialized. It is not required to be specified, but it may be useful in some cases.

Example:
  class Computer(username, password) {

      static users = Hash.new;

      # This method stores the users
      # inside the static hash created above
      func new(self, name, pwd) {
          users[name] = pwd;
      }

      # This method returns the users
      func get_users {
          return users;
      }
  }
__END__

Added the 'Array.flatten()' method to flatten an array.

Example:
   [[1,2,3], [4,5,6], 7, [[8,9], 10]].flatten;
   # returns: [1,2,3,4,5,6,7,8,9,10]

Minor code simplifications inside the parser and inside the bin/sidef