2.9.3 (unstable):

* signal:
  Deprecate slots().
  Please tell us if you really need this.
  (Murray Cumming)
  Deprecate emit_reverse().
  Please tell us if you really need this.
  (Murray Cumming)
* Benchmark: Update it and use boost::timer, and actually build it,
  but not built by default.
  (Murray Cumming)

Build:
* Fix the build on MSVC++ 2013 and 2015.
  (Chun-wei Fan) Bug #767777