[Bf-codereview] Paths and Windows Installer Fixes (issue4529081)

[nathan.letwory at gmail.com]

Otherwise a solid patch, except that this makes portable installs
completely impossible. I'd prefer to see Blender still check for config/
(startup.blend, bookmarks.txt, recent-files.txt) instead of now
defaulting to home dir only. Especially on portable installs you never
want Blender to write to the home dir (%APPDATA%).

If that gets fixed, the other changes are good.

For the installer there is no need to support the portable install
though - so no need to offer installation of config et al into install
dir.

http://codereview.appspot.com/4529081/