Updated VirtualBox guest additions
Integrated Portage 2.2 configuration changes

Now also using thin manifests for local repository:
only DIST entries are checksummed.
Disabled WiMAX and UWB (WUSB) support

WiMAX is represented by Intel's dead 2400 upstream
with many vulnerabilities, all for a single chip
support. Absolute majority of WiMAX hardware functions
as a modem, which does not require userspace or kernelspace
WiMAX support.

UWB is apparently not used anywhere, and kernel modules
require missing firmware.

Also, build-time updates related to libnl:3.