Please start commit message with port name.

[Vincent Habchi]

Ciao Petr,

> I'd like to propose to start commit messages with the port name. This helps very much to read them for example in the Timeline.
> 
> For example:
> 
> https://trac.macports.org/changeset/127794 -- Correct various bugs. Bump to revision 1.
> https://trac.macports.org/changeset/127795 -- Bump to version 2.1.4
> 
> could become:
> 
> - gdal: Correct various bugs. Bump to revision 1.
> and
> - postgis2: Bump to version 2.1.4
> respectively.

Fine. Ottima idea. 
Thanks for the suggestion!

Vincent