Update version and change for 0.12.3 release

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Changelog

+version 0.12.3
+  - kvm: Fix eflags corruption in kvm mode (Jan Kiszka)
+  - qcow2: Fix access after end of array (Kevin Wolf)
+  - ide save/restore pio/atapi cmd transfer fields and io buffer (Marcelo Tosatti)
+  - net: Monitor command set_link finds only VLAN clients, fix (Markus Armbruster)
+  - net: info network shows only VLAN clients, fix (Markus Armbruster)
+  - net: net_check_clients() checks only VLAN clients, fix (Markus Armbruster)
+  - net: Fix bogus "Warning: vlan 0 with no nics" with -device (Markus Armbruster)
+  - net: net_check_clients() runs too early to see -device, fix (Markus Armbruster)
+  - net: Remove unused net_client_uninit() (Markus Armbruster)
+  - don't dereference NULL after failed strdup (Jim Meyering)
+  - virtio-net: fix network stall under load (Tom Lendacky)
+  - json: fix PRId64 on Win32 (Roy Tam)
+  - fix inet_parse typo (Marcelo Tosatti)
+  - iothread: fix vcpu stop with smp tcg (Marcelo Tosatti)
+  - segfault due to buffer overrun in usb-serial (David S. Ahern)
+  - qcow2: Fix signedness bugs (Kevin Wolf)
+  - Do not ignore error, if open file failed (-serial /dev/tty) (Evgeniy Dushistov)
+  - pc-bios: update to newer version of (stable) seabios (Anthony Liguori)
+  - target-mips: fix ROTR and DROTR by zero (Aurelien Jarno)
+  - target-mips: fix CpU exception for coprocessor 0 (Nathan Froyd)
+  - tcg/mips: fix crash in tcg_out_qemu_ld() (Aurelien Jarno)
+  - target-mips: don't call cpu_loop_exit() from helper.c (Aurelien Jarno)
+  - virtio-blk: Fix error cases which ignored rerror/werror (Kevin Wolf)
+  - virtio-blk: Fix restart after read error (Kevin Wolf)
+  - virtio_blk: Factor virtio_blk_handle_request out (Kevin Wolf)
+  - cirrus: Properly re-register cirrus_linear_io_addr on vram unmap (Jan Kiszka)
+  - qcow2: Don't ignore qcow2_alloc_clusters return value (Kevin Wolf)
+  - qcow2: Don't ignore update_refcount return value (Kevin Wolf)
+  - qcow2: Allow updating no refcounts (Kevin Wolf)
+  - qcow2: Improve error handling in update_refcount (Kevin Wolf)
+  - qcow2: Fix error handling in grow_refcount_table (Kevin Wolf)
+  - block: Return original error codes in bdrv_pread/write (Kevin Wolf)
+  - qcow2: Return 0/-errno in qcow2_alloc_cluster_offset (Kevin Wolf)
+  - qcow2: Return 0/-errno in get_cluster_table (Kevin Wolf)
+  - qcow2: Fix error handling in qcow_save_vmstate (Kevin Wolf)
+  - qcow2: Fix error handling in qcow2_grow_l1_table (Kevin Wolf)
+  - win32/sdl: Fix toggle full screen (Herve Poussineau)
+  - win32: pair qemu_memalign() with qemu_vfree() (Herve Poussineau)
+  - vnc_refresh: calling vnc_update_client might free vs (Stefano Stabellini)
+  - Musicpal: Fix descriptor walk in eth_send (Jan Kiszka)
+  - Musicpal: Fix wm8750 I2C address (Jan Kiszka)
+  - fix savevm command without id or tag (Marcelo Tosatti)
+  - reduce number of reinjects on ACK (Gleb Natapov)
+  - QMP: Fix asynchronous events delivery (Luiz Capitulino)
+  - Documentation: Add missing documentation for qdev related command line options (Stefan Weil)
+  - pc: add driver version compat properties (Gerd Hoffmann)
+  - scsi: device version property (Gerd Hoffmann)
+  - ide: device version property (Gerd Hoffmann)
+  - QMP: Emit asynchronous events on all QMP monitors (Adam Litke)
+  - Fix QEMU_WARN_UNUSED_RESULT (Kevin Wolf)
+
 version 0.12.2:
   - Qemu's internal TFTP server breaks lock-step-iness of TFTP (Milan Plzik)
   - osdep.c: Fix accept4 fallback (Kevin Wolf)

VERSION

-0.12.2
+0.12.3