Add full path option to filetop.py command

I really like filetop.py. It is excellent tool.

Currently program displays FILE column with file name information, but in my case I have plenty of files with the same file name, but in different directory. Sample output (just two columns to simplify):

```
PID FILE
---- -----
100 file1
101 file1
```

From output I can't determinate what is the file path. I would really like to have output:

```
PID PATH
---- -----
100 /home/user1/file1
101 /home/user2/file1
```

This is feature request. Maybe add some command line switch, to display full file path.

Start by locating filetop.py and reading how it defines command-line options and formats the FILE column. Run the tool's existing help or usage path to understand its interface, then trace the file-name data used for each row. Done means an optional switch displays full paths in the output, including distinct paths for files with the same name.

Written by the indexing model from the issue text.