Moves iter forward by one character offset. Note that images
embedded in the buffer occupy 1 character slot, so
TextIter.forwardChar may actually move onto an image instead
of a character, if you have images in your buffer. If iter is the
end iterator or one character before it, iter will now point at
the end iterator, and TextIter.forwardChar returns FALSE for
convenience when writing loops.
Moves iter forward by one character offset. Note that images embedded in the buffer occupy 1 character slot, so TextIter.forwardChar may actually move onto an image instead of a character, if you have images in your buffer. If iter is the end iterator or one character before it, iter will now point at the end iterator, and TextIter.forwardChar returns FALSE for convenience when writing loops.