[El] Custom RPM repositories structure

[Mathieu Baudier]

> I completely agree, as far as QGIS is concerned. For GRASS, we use it on
> our servers, too. But this is not a major issue.

Anyhow, I think that we should always have the possibility to do some
"tricks" (like an additional temporary repo for the latest version of
GRASS if needed, etc.).
The fact that we will run in argeo's infrastructure will make it fairly easy.

The main point is to centralize the efforts: when I see the pain we
are currently going through with the (very helpful) developers of
GRASS to have the wxUI version running on CentOS, I would find it
completely inefficient no to put it in common...