New features

block/curl

Matthew Booth fixed a few bugs affecting modern curl, and now it works reliably
Daniel Barboza added timeouts
I added cookie support (for VMware vCenter)

block/ssh

I added this driver (for Xen)
It needs a bit of work still

copy-on-read

discard & fstrim

qemu has had excellent discard support for a few years
I added support for fstrim to ntfs-3g
Massively reduces the time taken to copy guests

json: paths

Less error-prone than ordinary qemu block paths

qcow2 v3

Several enhancements, but the most important is support for zero clusters