[File] New contributor's questions

[Vadim (vadcx)]

Hello, I want to contribute about a dozen of smaller formats and wanted 
to clarify a few things:

1. Preferred patch submission: via mailing list or the bug tracker?

2. Does the !:ext keyword have a meaning? I found it in Magdir/games but 
it's not in the man file.

3. File formats that do NOT have a magic but are otherwise identified by 
a known file name + extension: are they out of scope of this project? 
The closest thing I see is the "language" check in "man file"

4. I see there's a big definition file "Magdir/games", I plan to add 
about 10-15 definitions for single game. Should they go into the games 
too or is it okay to give it a separate definition file?

4.1 How does magic determine where one definition ends and the next one 
starts? (also not in man)

5. The string type can have a fixed length with "string/4" - limited to 
4 bytes. Is it relevant to performance vs unbounded string?

I will take "i dont know" as an answer too (as a hint to dig into the 
source code myself). I'll update the manual with the answers received.

Thank you

Vadim "vadcx"