[ref] Extract and promisify build-tree method (WIP)
[ref] Deduce devicename automaticaly + promise refactoring
[ref] Extract & refactor fetch-binary command
[ref] Extract put-dir method + promisify
[ref] Finish function extraction and promisification
[ref] Finish function extraction
[fix] Debug sync function
[fix] Correctly handle race conditions and lock FS watcher when adding files from remote
[doc] Add some function documentation
[ref] Harmonize promises
[ref] Promisify once in promise.coffee
Merge branch 'master' of github.com:cozy-labs/cozy-data-proxy