Add module with Windows symlink functions

Add module "ghar_win", containing Windows implementations of the
symlink-related functions of Python's "os" module.
Always ignore .gitignore and .gitmodules

Always ignore ".gitignore" and ".gitmodules" files when looping
over collections. You're generally not going to want these files
symlinked into your homedir.
Add "lstat" replacement to "ghar_win"

The ghar main module uses "os.lstat()" to figure out whether a directory
entry is a directory, file or symlink. Implement a ghar-specific
substitute for "lstat" that can detect symlinks.