NXDRIVE-13: Don't try to build app updater if either update site URL or server version is null, as they are both required for the update process
NXDRIVE-13: Fall back on default update site URL if the one returned by the server is null
NXP-13818: Move update test utility scripts to tools
Fix Pep8 warnings in tools
Fix inadvertently updated version
NXDRIVE-22: Enlarge settings dialog to prevent tab labels to be truncated under OS X
NXDRIVE-38: Take the parent checkstate if the parent is dirty
Merge branch 'master' of https://github.com/nuxeo/nuxeo-drive
NXDRIVE-13: Allow to override default server version and update site URL + fall back on default values when update info cannot be fetched (operation not deployed server side)