[GSoC15] Chained Text Boxes - Report Week 7

Hi,

Last week focus was on cursor motion and fixing some odd behavior.
What we got is that cursor can move from one box to another after an
Overflow and most of the code for positioning correctly exists.

What does not work and/or should be done next:
- the odd behavior I mentioned above is probably due, or at least includes,
the mysterious creation of empty paragraphs by the dozens after text
transfer. This is still an open issue.
- cursor transfer for pasting has not been handled yet.
- after transferring to the next box we are repositioned to the beginning
of the box after setting it to the right index.
- Backspace and arrow keys should be handled for cursor motion too.

Matteo