Rebrand Tor Browser's Window's Installer
The windows NSIS installer could use some rebranding as well!
TODO per build (stable, alpha, nightly):
- default install path and shortcut name (to allow side-by-side installation)
- release-$OS-$ARCH -> 'Tor Browser'
- alpha-$OS-$ARCH -> 'Tor Browser Alpha'
- nightly-$OS-$ARCH -> 'Tor Browser Nightly'