VirtualBox 4.3.0 Beta 2

# The following major new features were added:
* VMM: major rewrite of the VT-x code and the AMD-V code including many bug fixes and performance improvements
* GUI: extended messaging mechanism (new non-modal popup overlays used to show noncritical warnings and provide user with additional information)
* GUI: keyboard shortcuts management (input page of global preferences extended with possibility to edit general keyboard shortcuts for VirtualBox Manager and Virtual Machine)
* GUI: video capturing support
* Added USB touch device emulation
* Added SCSI CD-ROM emulation, including boot support
* VRDP: support for IPv6
* Guest Control: guest sessions now are running in dedicated, impersonated session processes (needs at least Guest Additions 4.3 installed)
* Guest Control: implemented IGuestFile support
* NAT: experimental virtual router mode: several VMs are attached to the same internal network and share one NAT service (see chapter 6.4, Network Address Translation Service (experimental)
# In addition, the following items were fixed and/or added:
* VMM: properly handle NMIs on Linux hosts with X2APIC enabled
* VMM: significantly improved performance of NetWare 5.x/6.x guests on host systems without nested paging support
* VMM: fixed losing host NMIs while in VT-x guest-context
* VMM: changed order of actions in emulated task switch
* GUI: update check uses https
* GUI: numerous minor internal cleanups and bug fixes
* GUI, VBoxManage: when unregistering a VM, also unregister the hard disk images which are used exclusively
* Snapshots: made live snapshots work again
* Teleportation: made it work again
* Storage: implemented AHA-154x compatibility mode in the emulated BusLogic SCSI HBA
* Storage: significantly improved performance of large ATAPI PIO transfers (BeOS, Minix 3 guests affected)
* Storage: added floppy formatting emulation (NB: cannot be used to change existing media geometry)
* Settings: global and per-VM default frontend configuration, useful to select the use of alternative VM frontends
* Settings: limit depth of snapshot tree to 250 levels, as more will lead to decreased performance and may trigger crashes
* Settings: the per-VM hwvirtextexcl setting has been replaced by a global hwvirtexclusive property
* Main: new event queue implementation which does not use the host’s native event queue for processing VirtualBox events anymore
*Main: use the XDG standard configuration folder instead of .VirtualBox on systems where it is appropriate
* Main: extension pack framework can now support loading HGCM modules
* VBoxManage: list more information about hard disk/DVD/floppy media, and support the --long option to show really all available details
* VBoxManage: added support for optional command line parameters for the automatic Guest Additions update
* VBoxManage: added support for listing active guest sessions, guest processes and/or guest files via guestcontrol list <all|sessions|processes|files>
* VBoxManage: added support for closing active guest sessions via guestcontrol session close --session-id <ID>| --session-name <name or pattern>|--all
* VBoxManage: added support for terminating active guest processes via guestcontrol process kill|close|terminate --session-id <ID>| --session-name <name or pattern> <PID> ... <PID n> or guestcontrol [p[s]]kill --session-id <ID>| --session-name <name or pattern> <PID> ... <PID n>
* VBoxManage: added support for watching guest sessions via guestcontrol watch
* 3D support: several fixes
* 3D support: several fixes for Mac OS X hosts
* OVF: several fixes
* Keyboard: fix for reporting key sequences like Ctrl+Alt+Del for the USB keyboard emulation
* Shared Clipboard/X11: support for BMP-format images, contributed by François Revol
* Windows hosts: don’t cause massive DPC latency (only on certain hosts; still needs improving)
* Windows hosts: consider symlinks when retrieving volume information
* Windows hosts: fixed an issue with USB2 devices being inaccessible when plugged into USB 3.0 ports
* Windows Additions: fixed misbehavior with guest display power management (WDDM driver only)
* Linux Additions: fixed udev detection in the init script with Linux 3.x kernels
* Windows guests: ability to track guest user idle times through the newly introduced event IGuestUserStateChangedEvent