VirtualBox 4.3.16 Build 95972

What's new in this version:

- VMM: fixed restoring 32-bit FPU state on 64-bit capable VMs and restoring guest FPU in raw-mode VMs
- GUI: properly restore normal/scale mode guest-screen size after exiting full-screen/seamless mode
- GUI: mini-toolbar should provoke less artifacts/conflicts with 3D guest rendering
- GUI: Mac OS X: Native full-screen multi-screen transition was able to blackout host-screens for nearly minute
- GUI: X11: Modern window managers should now use native full-screen multi-screen mapping API
- GUI: added extradata item for configuring the mouse capture behavior, see the manual for more information
- Storage: fixed a VBoxSVC crash when querying an iSCSI target with authentication configured
- Storage: fixed a rare data corruption during reads if another allocating write is running concurrently and accesses the same range
- Storage: fixed a rare crash for certain VHD images from other products
- Storage: fixed a rare release assertion when using the AHCI controller
- Floppy: fixed read errors and guest memory corruption when running under control of QEMM
- 3D: added experimental support for rendering on offline GPUs for Mac OS X host
- 3D: fixed white window appearing on entering FullScreen mode on OSX host
- 3D: fixed video recording support for 3D data regression
- 3D: fixes for MS Office 2013 support
- 3D: several fixes
- Bridged Networking: improved IPv6 support when bridging to a wireless interface
- NAT: prevent internal DNS service from stuck in host-resolver mode when host was switched from one network to another one while host was sleeping (Mac OS X hosts)
- NAT: preserve DF (if possible) and TOS when proxying outbound UDP datagrams
- NAT: don't let multicast datagrams out
- NAT: fixed handling of large incoming UDP datagrams on Windows hosts
- NAT: fixed handling of the RFC 1533 DHCP PAD option
- NAT Network: fixed inbound half-close on Windows hosts
- NAT Network: preserve IPv4 DF (if possible), TTL, TOS and IPv6 Hop Limit when proxying outbound UDP datagrams
- VRDP: fixed a rare crash when using remote audio input
- USB: fixed several regressions from 4.3.14
- Audio: made the HDA sound emulation work with certain OSX guests (e.g. Mountain Lion)
- Windows hosts: fixed startup problems on certain Windows hosts due to conflicts with anti-virus software
- Windows hosts: fixed 4.3.14 regression whereby AltGr stopped working for some people
- X11 hosts: made the extra key on Brazilian Thinkpads work
- X11 hosts: fixed a problem of input focus cycles and immediately released key presses in full screen mode
- Linux hosts: fixed flooding the kernel log with USB related messages when passing through certain USB devices to a VM
- Linux guests: stop applications crashing when drm_wait_vblank is called
- Linux guests: fix a crash in gnome-session
- X11 guests: do not start VBoxClient over an SSH connection
- X11 guests: added support for X.Org Server 1.16
- X11 guests: fixed a wrong parameter in the video driver which caused problems with full-screen X11 clients
- VirtualKD: introduced stub/loader device for speeding up Windows kernel debugging