Fix the mouse selection up-scrolling: fontHeight is an unsigned int, m_scrollY an int, now in the division, the int is casted to unsigned which isn't very nice when we want to scroll upwards (negative m_scrollY).
Fix the mouse selection up-scrolling: fontHeight is an unsigned int, m_scrollY an int, now in
the division, the int is casted to unsigned which isn't very nice when we
want to scroll upwards (negative m_scrollY).

renderer()->fontHeight() is used quite often, and I wonder if it wouldn't be
safer to make it return an int to avoid more mistakes..  what do you guys think?

CCBUG: 151795

svn path=/trunk/KDE/kdelibs/kate/; revision=733222

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