[#1930][#1931] Ability to save and retreive the configuration from

sflphone-client-gnome/src/config/accountwindow.c

...-client-gnome/src/dbus/configurationmanager-introspec.xml

sflphone-client-gnome/src/dbus/dbus.c

sflphone-client-gnome/src/dbus/dbus.h

sflphone-common/src/account.h

sflphone-common/src/dbus/configurationmanager-introspec.xml

sflphone-common/src/dbus/configurationmanager.cpp

sflphone-common/src/dbus/configurationmanager.h

sflphone-common/src/managerimpl.cpp

sflphone-common/src/managerimpl.h