CVS commit by aseigo: 

remove dead code, refactor panelbuttonbase into panelbutton, including
following coding conventions and getting rid of some of the indirection


  M +2 -2      Makefile.am   1.10
  M +1 -1      extensionbutton.cpp   1.8
  M +576 -20   panelbutton.cpp   1.16
  M +83 -6     panelbutton.h   1.14
  M +2 -1      servicebutton.cpp   1.30
  M +5 -5      servicemenubutton.cpp   1.11
  M +1 -0      urlbutton.cpp   1.20
  R            panelbuttonbase.cpp   1.61
  R            panelbuttonbase.h   1.26
  R            zoombutton.cpp   1.2
  R            zoombutton.h   1.2