reset hl on clear of document, or we won't get hl after reload/clear
reset hl on clear of document, or we won't get hl after reload/clear

svn path=/trunk/kdelibs/kate/; revision=137924

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