TB3: Tor Browser's official .mozconfigs.

Also:
Add an --enable-tor-browser-data-outside-app-dir configure option

Add --with-tor-browser-version configure option

Bug 31457: disable per-installation profiles

The dedicated profiles (per-installation) feature does not interact
well with our bundled profiles on Linux and Windows, and it also causes
multiple profiles to be created on macOS under TorBrowser-Data.

Bug 31935: Disable profile downgrade protection.

Since Tor Browser does not support more than one profile, disable
the prompt and associated code that offers to create one when a
version downgrade situation is detected.

Add --enable-tor-browser-update build option

Bug 40793: moved Tor configuration options from old-configure.in to moz.configure

Bug 41584: Move some configuration options to base-browser level