in order to maintain the null-style appropriately, if required
* finally fix #3040 for real (a single style is now maintained at all times
for non-stylable textviews)
* the caret is now being drawn with the correct size, even if it is on
the empty line at the end of the buffer and a specific font size has been
requested
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30532 a95241bf-73f2-0310-859d-f6bbb57e9c96