RhodeCode CE/EE

Actually a customer requested that: https://rhodecode.tenderapp.com/help/discussions/problems/9225-rc-352-download-a-largefile-downloads-in-fact-the-sha-1-of-the-hglf-folder

Internally AFAIR we have already code that can fetch largefiles from the LF store of Mercurial. It's just a small task of serving those files instead of the sha of the file given.

How it should work ?
When users clicks on a largefiles displayed in file view, the content of such file is a hash, this hash points to a largefile store hash of this file.
Under download as raw button we should server the content of that file at this sha, instead of current content which is a plaintext file with sha stored inside.