KAL: Fix the installation path of the widgets and don't install kalsoundloader.h
KAL: Fix the installation path of the widgets and don't install kalsoundloader.h

pranavrc/example-gluon,KDE/gluon,pranavrc/example-gluon,KDE/gluon,pranavrc/example-gluon,cgaebel/gluon,cgaebel/gluon,KDE/gluon,cgaebel/gluon,pranavrc/example-gluon,KDE/gluon,cgaebel/gluon