CVS commit by bieker: 

* cleaned up the interface
* KLanguageButton no longer derive from QPushButton (so people can't just
  cast it to QPushButton anymore).
* added documentation.


  M +11 -5     kcmlocale.cpp   1.103
  M +1 -1      kcmlocale.h   1.40
  M +70 -60    klanguagebutton.cpp   1.7
  M +91 -27    klanguagebutton.h   1.3