Changes 3.0.17:
* Replace thread-unsafe use of sigc::slot where relevant with thread
  safe callback classes
* Compile fixes for gcc-4.3
* Fix '=' for '==' error
* Remove unnecessary debugging code
* Update config.guess, config.sub, install-sh, missing and
  mkinstalldirs to automake-1.9
* Correct comments in pipes.h

(adam)