Volume sliders & Cleanup of warnings

sflphone-gtk/configure.ac

sflphone-gtk/pixmaps/Makefile.am

sflphone-gtk/pixmaps/dial.svg

sflphone-gtk/pixmaps/mic.svg

sflphone-gtk/pixmaps/speaker.svg

sflphone-gtk/src/Makefile.am

sflphone-gtk/src/accountlist.c

sflphone-gtk/src/accountwindow.c

sflphone-gtk/src/actions.c

sflphone-gtk/src/actions.h

sflphone-gtk/src/calllist.c

sflphone-gtk/src/calltree.c

sflphone-gtk/src/calltree.h

sflphone-gtk/src/configwindow.c

sflphone-gtk/src/dbus.c

sflphone-gtk/src/dbus.h

sflphone-gtk/src/dialpad.c

sflphone-gtk/src/main.c

sflphone-gtk/src/mainwindow.c

sflphone-gtk/src/mainwindow.h