Removing "$Id$" lines

[Lawrence Velázquez]

> On Nov 1, 2016, at 4:59 AM, Marko Käning <mk-macports at posteo.net> wrote:
> 
>> On 01 Nov 2016, at 02:02 , Rainer Müller <raimue at macports.org> wrote:
>> 
>> buildbot: ignore
> 
> +1
> 
> I’d also suggest to use this also to specify which buildbots should be used for a commit:
> 
> buildbot: Mavericks Sierra
> 
> I think that can be very helpful in some cases.

While I agree in principle that our committing should not be hampered by
the buildbot and would welcome another solution, I'm not crazy about the
idea of polluting our (permanent!) commit history with transient
administrivia like this.

vq