v1.4.1-alpha.1

First alpha release:

• tabs
• improved about dialog (Win/Linux now have copy button)
• ftp-related fixes (but ftp will be disabled)
• electron-builder configuration options for mac/win/linux
• new sendFakeCombo that allows to send menu combos from the renderer process
• look improvements: new icon, app now has a splash screen
• devtools disabled in packaged release