New file: array list

    Added the primary function declaration for array list class.
    That's what I want to implement, such as binary search, and some sorting
    functions.
Upgrade: file structure
    Move all tools(include some system header) into single tools file.
    Now all testing file just need the tool.h and the target class file.

New file: array list test file
    Basic testing code added.
Upgrade: arraylist.h

    Added some skeletons for the function.
Upgrade: makefile

    Added the arraylist into makefile

Upgrade: arraylisttest

    Complete the test code for setting and getting.

Upgrade: arraylist

    Fix some bugs.
Upgrade : arraylist

    new function: swap
        function to swap two elements by their index.

    new function: bubble sort
        just a bubble sort function, without testing.
Upgrade: arraylist

    Complete: bubble sort function
    Complete: swap function