Executable flagging patch

[Gustavo Niemeyer]

> This is because generate_changeset still uses the ChangeUnixPermissions
> object, which affects all permissions.  Instead, I think a new
> ChangeExecuteBit object should be introduced that only affects the
> execute bit.

Next we'll have ChangeReadBit, ChangeWriteBit, ChangeSuidBit, and so on?

I don't think this is really necessary, or wanted, even because we're
not doing anything else regarding permissions right now.

-- 
Gustavo Niemeyer
http://niemeyer.net