2.13.4:

* Correct initialization when using --disable-deprecated for reduced code-size
 on embedded devices. (Johannes Schmid, Openismus)
* Glib::ObjectBase::is_derived_() is now public, though it is still only for
 internal use. This allows us to do some optimization of default signal handlers and
 vfuncs.
 (Armin Burgmeier, Openismus)
* Options: Don't overwrite default arguments. This change was lost in
 March 2006, but now it is back.
 (Armin Burgmeier)
* Dispatcher: Several minor implementation improvements. (Daniel Elstner)
* ustring: Minor improvements. (Daniel Elstner)
* Documentation: Actually use the signals documentation again.
 (Armin Burgmeier, Openismus)
* Build:
 - Fix code generation when using the latest m4, and functions named
 mkstemp, as experienced on Ubuntu Feisty.
 Bug #397167 (Dodji Seketeli, Daniel Elstner)
 - helperlist.h: Avoid warnings about a shadowed member.
 Bug #420316 from Bradley Bell.
 - utility.h: Avoid a warning about a redundant declaration.
 Bug #420339 from Bradley Bell.