Generate a python program that has the following intention:

The intention of the program is to find the maximum sum of a sublist of a given list. The program first defines a function called max_sublist_sum that takes a list as input and returns the maximum sum of a sublist.

The program then defines two variables: biggest_until_now and max_ending_here. biggest_until_now keeps track of the largest sum that has been seen so far, while max_ending_here keeps track of the largest sum that can be achieved by adding the current element to the elements seen so far.

The program then loops through each element in the list and updates max_ending_here and biggest_until_now. First, it adds the current element to max_ending_here. Then, it compares max_ending_here to biggest_until_now and sets biggest_until_now to the larger of the two.

Finally, the program returns biggest_until_now, which is the maximum sum of a sublist of the given list.