### Please describe the problem.
Since the Win10 Creators Update, if Developer Mode is enabled, symlinks can be created without elevated privileges. During cloning of a repository with symlinks, git detects this and creates symbolic links, whereas in the past it would simply create text-like files with a path.

When symlinks are created, git-annex breaks in many wonderful ways. The symlinks are not detected as annexed files and `git annex info` shows that no files are in the annex.

### What steps will reproduce the problem?
On a Windows 10 machine with Creators update (v1709) and Developer mode enabled, do a `git clone` of a git-annex repository. Then `git annex init` and `git annex info`.

Additionally, if a `git annex sync` is performed, the symlinks are deleted.

### What version of git-annex are you using? On what operating system?
v6.20180112 on Windows 10 with update 1709.

### Please provide any additional information below.
Since the aforementioned Windows update (commonly referred to as Creators Update), the mklink command can be executed without requiring elevated privileges if Developer mode is enabled.
See the following two articles for some background:

- [Windows 10 Creators Update: Symlinks without elevation
 [ghacks.net]](https://www.ghacks.net/2016/12/04/windows-10-creators-update-symlinks-without-elevation/)
- [What Is “Developer Mode” in Windows 10? [howtogeek.com]](https://www.howtogeek.com/292914/what-is-developer-mode-in-windows-10/)

It would seem that git detects this and does not disable symlinks as git-annex expects it to do on Windows.

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)
Yes. I use it frequently on multiple platforms.

