Mir 0.13.0

• Enhancements:
  ◦ New demo clients for input testing: mir_demo_client_eglsquare and
    mir_demo_client_target.
  ◦ Demo clients: mir_demo_client_tooltip, mir_demo_client_animated_cursor
  ◦ mir_demo_client_fingerpaint now processes input asynchronously to
    drawing for a more fluid experience.
  ◦ New, default window manager in mir_demo_server
  ◦ mir_demo_server option (--arw-file) to make socket filename globally rw
  ◦ mir_demo_server demonstrates use of config file
  ◦ Added support to mir_proving_server for rendering window title strings
  ◦ Demo servers (mir_proving_server, mir_demo_server): Introduce support
    for Alt+` switching of windows in multi-window clients.
  ◦ Added client API support for constructing input method surfaces.
  ◦ Introduce "buffer streams" properly. This is a generalization of the
    most basic functionality of a surface.
  ◦ Log useful OpenGL information on server start-up.
  ◦ Add support for HWC 1.4
  ◦ Add display and fencing information to the layers in the HWC report
  ◦ Add a report_vsync method to display report
  ◦ Support for second display when running on "android" driver stack
  ◦ Server buffering strategy is configurable by --nbuffers=N
    (or environment MIR_SERVER_NBUFFERS=N)
  ◦ Explicit support for configuring window management in libmirserver.
  ◦ Remove surface configurator & placement strategy configuration points
  ◦ Added experimental environment variable MIR_CLIENT_INPUT_RATE=Hz for
    tweaking the input resampling rate a client experiences (0 = off).
    Also raised the default input rate from 55Hz to 59Hz for visibly
    smoother touch scrolling.
  ◦ Added keymap setting support for surfaces.
  ◦ Improved automated testing of latency.
  ◦ Replaced and rewrote automated ABI checking.
  ◦ New client APIs for basic window management; setting window titles,
    self-resizing, size constraints and changing type.
  ◦ Introduced dynamically loadable input platforms.
  ◦ Work towards libinput integration
  ◦ Added proof-of-concept support for Snappy packaging for Ubuntu Core.
  ◦ Drop support for C++11. Now C++14 is required to build Mir.
  ◦ Deprecated MirEventDelegate. Now you just pass the two fields as
    parameters directly to mir_surface_set_event_handler().
  ◦ Legacy functions for creating surfaces marked deprecated
  ◦ Minor redesign of the new input event API introduced in 0.10/11,
    so that identifiers are shorter and less convoluted.
  ◦ Drop libmirclient dependency on client-platform drivers
  ◦ Drop libmirserver dependency on client-platform drivers
  ◦ Use the ABI version in platform library names and packages
  ◦ Rework to reduce "abstraction leaks" in the graphics platform
  ◦ Add thread sanitizer build option
  ◦ Update KVM Instructions
  ◦ Update CMAKE to use CMAKE_*_OUTPUT_DIRECTORY
• ABI summary: Servers need rebuilding, but clients do not;
  ◦ Mirclient ABI unchanged at 8
  ◦ Mircommon ABI bumped to 4
  ◦ Mirplatform ABI bumped to 7
  ◦ Mirserver ABI bumped to 31
• Bug fixes: See below.