In case we have a git clone from Linux that is accessed via cygwin git
the files executable status will be derived from the file content (shebang)
and won't match the git repo, leading to a initially dirty tree.
This can be worked around by setting "core.filemode=false", but let's try
to match the cygwin permissions with the in-repo permissions so this isn't
needed.
Includes a gimp script to convert all xcfs in "splash/" to jpgs and write out a
(windres) resource file (splash_frames.rc2) and header file (splash_frames.h)
