OSX: provide initial icons for DMG.
Installer: fix potential crash on Widget-item iteration. Streamline diskutil-output handling on OSX for device enumeration. Make sure enumerated devices are available in the UI
Merge pull request #3 from srmo/osx-app-icons

OSX: provide initial icons for DMG.
Merge pull request #2 from srmo/fix-disc-enumeration

Installer: OSX device-enumeration streamlined and fix potential crash on Widget-item iteration.