forward port SVN commit 511726 by alund:
forward port SVN commit 511726 by alund:

Make updateStyle() work: colors can be unset, and so can other items if we
reset to default (oh, and call it too in the latter case)

CCBUG: 117479

svn path=/trunk/KDE/kdelibs/kate/; revision=555680

hlamer/kate,DickJ/kate,DickJ/kate,cmacq2/kate,jfmcarreira/kate,jfmcarreira/kate,sandsmark/kate,jfmcarreira/kate,DickJ/kate,hlamer/kate,hlamer/kate,sandsmark/kate,sandsmark/kate,DickJ/kate,sandsmark/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,cmacq2/kate,cmacq2/kate,hlamer/kate