nw.js update to 0.28.1
As discussed off-list, this fixes a bug with older nw.js versions (including 0.24.4 which is what we currently use) not being able to open the floating dialogs on Windows for some hardware configurations. Exact cause of this issue is unknown, but it's 100% reproducible when I run Purr on Windows 10 using either my Intel NUC or the latest VirtualBox version. Upgrading to 0.28.1 fixes the issue on both systems, and I didn't notice any other regressions due to the update on Linux/Mac/Windows either.