Merge branch 'modesetting-import' into master

This reintroduces a "hardware" driver to the xfree86 directory.
Unlike the drivers that xorg used to include in the source tree, that
needed independent release schedules to get hardware support out the
door, the modesetting driver shouldn't change much as new hardware
gets released.  A lot of what this driver needs to do is just keep up
with server ABI changes.

This import was done by taking xf86-video-modesetting-0.9.0, and
running this script with 'git-filter-branch -f --tree-filter
~/bin/modesetting-filter':

mkdir -p hw/xfree86/drivers/modesetting

rm -f README autogen.sh configure.ac Makefile.am .gitignore
rm -f man/Makefile.am

mv man/modesetting.man hw/xfree86/drivers/modesetting/
mv COPYING hw/xfree86/drivers/modesetting/
mv src/* hw/xfree86/drivers/modesetting/