Fix a Bug
Fix a Bug

It may crash on line 221 or 248:
int pos = start - (int)mSkinRangeStart + (getLineSize() - getTrackSize()) / (((int)mScrollRange - 1) * 2);
Integer division by zero.
Which happens in our game.
And in fuction notifyMouseWheel, this if-statement exists.
Maybe you think when mScrollRange < 2, ScrollBar is invisable, so you leave the statement out.
But In some condition,  this viewpoint is wrong.
scrawl/mygui,fmwviormv/mygui,fmwviormv/mygui,fmwviormv/mygui,al2950/mygui,fmwviormv/mygui,scrawl/mygui,scrawl/mygui,scrawl/mygui,al2950/mygui,al2950/mygui,al2950/mygui