ICNS/JPEGTranslators: add Jamfile deps to lib headers

* Add Jamfile dependency to LIBPNG headers on icns_png.c;
* Add Jamfile dependency to LIBJPEG headers on JPEGTranslator.cpp
  be_jdatasrc.c
Jamfile/makefile-engines:replace -nostart with -shared

Starting from our GCC 4.7.3 the shared library -nostart option is not
valid anymore. Replace it with -shared one that works in GCC2 build
environment too.
virtio: integrate into the build and image

* device_manager: scans busses/virtio for network device types
  and scsi controllers.
Virtio: added drivers for PCI busses, bus manager and block device.

* the Virtio PCI bus driver exposes a Virtio controller to the Virtio bus manager,
which in turn exposes a Virtio device consumed by Virtio drivers. Drivers follow the
new driver model.
* virtio_block handles Virtio block devices under disk/virtual/virtio_block/x/raw.
* Here is the Qemu command line option for Virtio disk devices:
  -drive file=haiku.image,if=virtio
* the PCI bus driver currently supports only legacy interrupts (no MSI(-X) yet).
* There is room for improvements in the bus manager:
  - it notifies the host for each queued request, which isn't optimal.
  - transfer descriptors should probably be simply preallocated (they are nicely
    leaked at the moment).
  - indirect descriptors are not supported yet.
and in the block driver:
  - get the id of the disk.
  - implements flushing the cache.
  - improves dma restrictions.
  - do_io() should use a page for header descriptors instead of malloc(), which
    could cross boundaries.
* The device manager tries to guess the driver based on the PCI device type, this
implies having to declare the "busses/virtio" path for each possible type
provided by Virtio. Thus future driver additions might require patching the device
manager.
* virtio.h is still private, the API is subject to changes.
* virtio_pci.h, virtio_blk.h, virtio_ring.h are copied unchanged from FreeBSD.
Merge branch 'virtio'
virtio_pci: build not only for x86.
app_server: added more debug output on screen change problems.
When an exception/breakpoint is hit, activate...

...the team window. Resolves #9797.
KeymapSwitcher opt.package updated to 1.2.7.10

* Fixed hotkeys selector resize issue occured on latest Haiku revisions;
* Fixed handling of system-wide keymap switch mode;
* Remove BDragger from the Deskbar replicant.
DRAFT: some attempt to force usb_audio to work.

adapting audio driver for work with new ohci bus manager.
Activate debug tracing, add more debugging support
Draft implementation of OHCI isochronous transfers

Set of changes from previous coding during April-May 2012
DEBUG: disable some modules for dev. time