2.2.11 (stable):

* Fix comma operator in libsigc++ lambda expressions.
  Andris Pavenis) Bug #342911
* Added SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE.
  This allows most uses of libsigc++'s lambda expressions to be 
  replaced by standard C++11 lambda expressions.
  (Kjell Ahlstedt) Bug #672555.
  Thanks to Chow Loong Jin, who posted similar code on libsigc-list.
* Use std::size_t and std::ptrdiff_t instead
  (Kjell Ahlstedt)
* Fix 'make check' with gcc 4.7.
  (Kjell Ahlstedt)
* Enable test_lambda in 'make check'.
  (Kjell Ahlstedt) Bug #669128.