### Please describe the problem.
When two identical files are annexed and one of them is dropped, both files are gone (one dangling symlink is left). This may be intentional (the checksums are the same after all), but then is there a way to drop one of the files?

### What steps will reproduce the problem?

    mkdir annex
    cd annex
    git init
    git annex init
    mkdir a b
    dd if=/dev/urandom of=a/data.bin count=2048
    cp a/data.bin b
    git annex add a/data.bin b/data.bin
    git commit -m "Added raw data."
    git annex drop --force a/data.bin
    file b/data.bin

### What version of git-annex are you using? On what operating system?

git-annex version: 5.20140831+b1  
build flags: Assistant Webapp Webapp-secure Pairing Testsuite S3 WebDAV Inotify DBus DesktopNotify XMPP DNS Feeds Quvi TDFA CryptoHash  
key/value backends: SHA256E SHA1E SHA512E SHA224E SHA384E SKEIN256E SKEIN512E SHA256 SHA1 SHA512 SHA224 SHA384 SKEIN256 SKEIN512 WORM URL  
remote types: git gcrypt S3 bup directory rsync web webdav tahoe glacier ddar hook external  
local repository version: 5  
supported repository version: 5  

Distributor ID: Debian  
Description:    Debian GNU/Linux testing (jessie)  
Release:        testing  
Codename:       jessie  

> If you don't want git-annex to de-duplicate files you can use a backend
> such as WORM. Here it's behaving as expected, so [[done]]. --[[Joey]]
