Integrate dbus-c++ and iax2 libraries in the main build system

libs/dbus-c++/debian/copyright

libs/dbus-c++/debian/dbus-c++-1-dev.install

libs/dbus-c++/debian/dbus-c++-1.install

libs/dbus-c++/debian/docs

libs/dbus-c++/debian/rules

libs/dbus-c++/depcomp

libs/dbus-c++/doc/Doxyfile.in

libs/dbus-c++/doc/Makefile.am

libs/dbus-c++/doc/html/Makefile.am

libs/dbus-c++/examples/Makefile.am

libs/dbus-c++/examples/echo/Makefile.am

libs/dbus-c++/examples/echo/README

libs/dbus-c++/examples/echo/echo-client.cpp

libs/dbus-c++/examples/echo/echo-client.h

libs/dbus-c++/examples/echo/echo-introspect.xml

libs/dbus-c++/examples/echo/echo-server.cpp

libs/dbus-c++/examples/echo/echo-server.h

libs/dbus-c++/examples/glib/Makefile.am

libs/dbus-c++/examples/glib/dbus-browser.cpp

libs/dbus-c++/examples/glib/dbus-browser.h