[PATCH 0/5] git-tar-tree: add symlink support

Since symlinks can be stored inside GIT, git-tar-tree should properly handle them, too. The first three patches do a bit of cleanup to make adding symlink support easier. The fourth patch actually dirties the code, also to make the fifth one easier. :) I just couldn't think of a better way to split the changes and a combined patch of 4&5 did too much at once.

If a link target is longer than 100 chars than an extended header is created. Because of the way git-tar-tree handles extended headers that means the sum of path and target of a symlink must be less than about 490 chars. This is not a limitation of the archive format, so we can fix it later.

Rene