OutputDevice code reorganization

Hi all,

In my ongoing efforts to refactor, document, understand and generally
cleanup OutputDevice, I'm finding it increasingly hard to keep track of the
way the files are laid out.

Currently the files have very little order. The functions are split out
into 6 seperate outdevx.cxx files (where x is a number).

I have pushed a private branch to propose a change to the layout:

http://cgit.freedesktop.org/libreoffice/core/log/vcl/?h=private/tbsdy/outdev

I have moved outdev.cxx to outdev6.cxx to the directly vcl/source/outdev,
and into the following files:

outdev.cxx (for a variety of clipping functions, etc)
outdevnative.cxx
outmap.cxx
bezier.cxx (for two shared bezier functions)
tworect.cxx
bitmap.cxx
curvedshapes.cxx
hatch.cxx
gradient.cxx
line.cxx
polyline.cxx
polygon.cxx
pixel.cxx
rect.cxx
wallpaper.cxx
blend.cxx
transparent.cxx
mask.cxx
text.cxx
font.cxx

I think this largely helps split up the file in a more sensible layout.

I realise that there is some concern that this might make merging Apache
Open Office code with our own, but I feel that the file layout
rearrangement really aids in code clarity. Certainly I find it helpful to
just be able to look up specific functions in a more intuitive to
understand file.

I know that it builds - I would just like to get some feedback on the
layout before I push it out to master.

Chris Sherlock