Support laptop Function (Fn) key

```
(This is an enhancement request.)

Many laptops feature a specific key named Function situation near the Control,
Alt, or OS key (Windows, Command, etc). I would like logkeys to identify for
debugging purposes when this key is pressed similar to how it regards Shift,
Ctrl or Alt.

logkeys 0.1.1a
Ubuntu 10.10 i386

When I press the Function key ONE time on my keyboard followed by , I
get the following output in the log file. Notice, I pressed Ctrl-C to exit.

2011-05-17 06:01:30+0000 >

2011-05-17 06:01:32+0000 > ^C

Thanks

```

Original issue reported on code.google.com by `byu...@gmail.com` on 17 May 2011 at 6:03

Attachments:
- [keymap.txt](https://storage.googleapis.com/google-code-attachments/logkeys/issue-58/comment-0/keymap.txt)
- [devices.txt](https://storage.googleapis.com/google-code-attachments/logkeys/issue-58/comment-0/devices.txt)
- [dumpkeys.output](https://storage.googleapis.com/google-code-attachments/logkeys/issue-58/comment-0/dumpkeys.output)

Start by examining logkeys' keyboard event handling and the attached keymap.txt, devices.txt, and dumpkeys.output files. Determine whether the laptop's Function key produces an identifiable event that can be distinguished from existing modifiers. Done means pressing Fn produces a useful log entry similar to Shift, Ctrl, or Alt.

Written by the indexing model from the issue text.