upgraded file-manager
removed duplicate file manager library (already in enketo-core)
belongs to previous commit
upgraded enketo-core with fix for https://github.com/MartijnR/enketo/issues/301
(grumble) upgraded enketo-core with fix for https://github.com/MartijnR/enketo/issues/301
Merge branch 'master' of https://github.com/MartijnR/enketo into production