[GSoC15] Chained Text Boxes - Report Week 5

Hi there,
from this week:
- implemented underflow handling
- created appropriate classes reducing SdrTextObj's responsibility and
separating editing vs non-editing behavior

Next steps are:
- having a look at why some automatic tests in sd fail (a clue is that
current overflow/underflow testing code has reverted some ad hoc fixes that
set paper size at specific values. So I should probably look at this commit
<http://cgit.freedesktop.org/libreoffice/core/commit/?h=feature/gsoc14-draw-chained-text-boxes&id=f907f74a5ef3372f275c2ef5cb51d38823383e34>
)
- implementing cursor motion though a chain of boxes and keeping style
sheets consistent

M.