pack_file object
This method will add a file to the currently open pack file.
bool add_file(string file_on_disk, string internal_name)
Parameters:
file_on_disk
The filename stored on disk to add to the pack file.
internal_name
An internal storage name that should be used to refer to it inside the pack file.
Return value:
true on success, false on failure.
Remarks:
The pack file must be opened in write mode with the create method for this operation to be successful.
The internal_name parameter is simply used to refer to the file inside the pack. This can contain any characters and can be laid out in any format.
Example:

    // Create a pack file and add some test files.

    void main()
    {
    pack_file test;
    test.create("pack.dat");
    test.add_file("test1.txt","t1");
    test.add_file("test2.txt","t2");
    test.add_file("test3.txt","t3");
    test.close();
    }