This is a maintenance release. The following items were fixed and/or added:

- GUI: fixed keyboard shortcut handling regressions (Mac OS X hosts only; bugs #15937 and #15938)
- GUI: fixed keyboard handling regression for separate UI (Windows hosts only; bugs #15928)
- NAT: don't exceed the maximum number of "search" suffixes. Patch from bug #15948.
- NAT: fixed parsing of port-forwarding rules with a name which contains a slash (bug #16002)
- NAT Network: when the host has only loopback nameserver that cannot be mapped to the guests (e.g. dnsmasq running on 127.0.1.1), make DHCP supply NAT Network DNS proxy as nameserver.
- Bridged Network: prevent flooding syslog with packet allocation error messages (bug #15569)
- Audio: now using Audio Queues on Mac OS X hosts
- Audio: fixed recording with the PulseAudio backend (5.1 regression)
- Audio: various bugfixes
- Audio: various bugfixesSnapshots: fixed regression in 5.1.4 for deleting snapshots with several disks (bug #15831)
- Snapshots: crash fix and better error reporting when snapshot deletion failed
- Storage: some fixes for the NVMe emulation with Windows guests
- API: fixed initialization of SAS controllers (bug #15972)
- Build system: make it possible to build VBox on systems which default to Python 3
- Windows hosts: detect certain cases of REGDB_E_CLASSNOTREG errors and print a helpful error message
- Windows hosts: adapted to changes in Windows 10 build 14901 (bug #15944)
- Windows hosts: better support for processor groups on Windows 7 and later which is required on certain hosts with many CPUs
- Windows installer / Additions: added option to prevent creating of start menu items (bug #15922)
- Windows Additions / VGA: if the guest's power management turns a virtual screen off, blank the corresponding VM - window rather than hide the window
- Windows Additions: fixed a generic bug which could lead to freezing shared folders (bug #15662)
- Linux hosts / guests: fix for kernels with CONFIG_CPUMASK_OFFSTACK set (bug #16020)
- Linux Additions: don't require all virtual consoles be in text mode. This should fix cases when the guest is booted with a graphical boot screen (bug #15683)
- Linux Additions: added depmod overrides for the vboxguest and vboxsf kernel modules to fix conflicts with modules shipped by certain Linux distributions
- X11 Additions: disable 3D on the guest if the host does not provide enough capabilities (bug #15860)