German tanslatin

Add and fix german translation
Merge pull request #668 from DepaMarco/develop

Add Italian translations for plugins: 'auth.phpbb', 'auth.radius' and 'auth.remote'
Fix isWriteable function
Fix rename()

Return true or false
Merge pull request #662 from Vorlif/develop

German tanslation
Test that exif_read_data exists in PThumb orientation functions. Added a startup test to suggest installing this PHP extension.
Fix #664
Update phpCAS version 1.3 stable
Fix domain separator. User decide to use / or \
Handle multiple selection in InfoPanel : display simple elements previews, plus the standard action bar inc. Download button. Fix #653
Decorate "Click here"
Restore folding of the right ("info") panel. And thus restore Download and Share actions in the right-click menu. Added an optional foldingMinSize to splitter to keep a different minSize in unfolded mode. Fix #656
Merge branch 'develop' of https://github.com/pydio/pydio-core into develop
Fix logout button
Fix logout button
Rename Dashboard to "My Account", more intuitive. Fix #655
Merge remote-tracking branch 'origin/develop' into develop
Fix Resource not Allowed error in webodf frame
Better widget detroy (guiActions and focusables were not cleanly deregistered).
TODO: check legacy themes, the FilesList actions have moved from default to id-actions actionbargroup.
Update class.CAS_LoginForm.js
Save Expand state - Fix #669