ARM: work around too many libgcc objects when linking libroot

jam fails in execve() trying to run the command due to
a too large arguments list because of the many objects in libgcc.

We split them into two intermediate objects,
then we link them to libroot.
Minor style cleanup.
libshared: Factored out driver settings class from net_server.

* The new class is called DriverSettingsMessageAdapter which can translate
  between a driver_settings file, and a BMessage.
* The net_server Settings class is now just using this class.
Add definitions for PPC repositories and package infos