In a from-scratch build, when running the configure script, which then
runs the set_soenv script, the default_images symlink (that is passed
to this function in the form of a Windows path, for some reason) does
not exist yet, and realpath fails anyway. So don't bother calling
realpath on Windows paths.

Although I don't know whether it then will cause a problem that the
cygpath -m call won't be able to expand the symlink as it doesn't
exist anyway. This is a mess. And if cygpath -m expands symlinks
anyway, why is the realpath needed at all?

This is to allow use of ccache by specifying something like:

  export CC="ccache C:/path/to/cl.exe"
  export CXX="ccache C:/patch/to/cl.exe"

before running ./autogen.sh

otherwise a removed file would be recreated

+ use "git log" again to get weekly commit logs
+ use "git rev-list" only with --rev-list option; useful to list differences
  between branches

http://lists.freedesktop.org/archives/libreoffice/2011-April/010408.html

use "git rev-list --pretty=medium" instead of "git log"
to be able to use origin/libreoffice-3-4 ^origin/libreoffice-3-3
to generate list of changes that are in 3.4 but not in 3.3

FIXME: we should find another way to tell dowload the right version
of used sources

based on libreoffice/build/bin/lo-pack-sources; still need some clean up

The --with-distro options might come from bin/build-ooo in a "build"
style build, and in that case, the relevant configure options are
already on the command line, too.

See http://perldoc.perl.org/functions/readdir.html .