Add cmd.exe support

[zippy1981]

I'm not sure if you can edit te history of a cmd.exe session, but that would be a cool feature.

[raoulvdberge]

This wouldn't work as histsync uses bash-preexec, which uses bash.

[zippy1981]

So ok a different client must be written. It could still talk to the same server that just stores lines of text.

[raoulvdberge]

Yes. I don't know if cmd.exe has any kind of API to make this work though.