VirtualBox 4.1.12.77218

# The following items were fixed and/or added:
* VMM: fixed VERR_NOT_SUPPORTED and VERR_RAW_MODE_INVALID_SMP guru meditation due to an invalid reschedule to raw mode
* VMM: fixed PDMCritSectLeave guru meditation under rare circumstances with SMP guests
* VMM: proper Math Fault handling with certain legacy guests
* NAT: fixed a socket leak under certain conditions
* Storage: better sanity check against reading beyond end-of-file
* Audio: fixed a crash in the NUL audio backend (4.1.10 regression)
* HGCM: fixed a crash during savestate under rare circumstances
* VBoxSVC: several locking fixes
* VBoxManage: return the correct error code if controlvm savestate failed
* Guest Additions: VBoxService should not crash on exit (4.1.10 regression)
* Windows Additions: set the correct time stamp when a file is closed
* Windows Additions: better help if the DirectX backups are not properly installed
* Linux Additions: Linux 3.4-rc1 compile fixes