VirtualBox 5.1.4 Build 110228

What's new in this version:

- GUI: show actual VM uptime in the session information window
- Audio: re-enabled speakers for Mac OS X guests (5.1.0 regression; bug #15611)
- Audio: fixed crashes under certain conditions
- USB: fixed a hang under certain conditions
- USB: fixed a hanging guest under certain conditions
- PIIX4: implemented dummy SMBus controller to prevent annoying Linux kernel warnings about uninitialized SMBus base address
- NVMe: several fixes to improve stability, fixed a crash while saving a VM state
- VMDK: Fixed an issue creating fixed size images with certain sizes and the Split2G option enabled
- VHDX: fixed cloning images with VBoxManage clonehd
- Storage: Fixed broken bandwidth limitation when the limit is very low
- EFI: fixed sending debug messages in the EFI firmware if a serial port is enabled
- OVF: when importing appliances, make sure that the version of the embedded VirtualBox-specific settings is processed, to get the default settings handling right
- VBoxManage: Don't try to set the medium type if there is no change
- Linux installer: fixed some scripting issues
- Linux installer: fixed a path issue on certain Linux distributions
- Windows hosts: fixed corrupted mouse pointers with some Linux and Solaris guests
- Linux Additions: made the video driver work on 32-bit guests with large video memory sizes
- Linux Additions: made the video driver work on kernel 4.7 and later
- Linux Additions: converted a failure message to an informational one when drivers could not be stopped during upgrade
- Linux Additions: made the video driver work around an X server bug which cause screen refresh to stop
- Windows Additions: auto-resizing fixes for Windows 10 guests
- Windows Additions: fixed VBoxTray problems with Windows 2000