Janky Iceweasel Fork: Spelling Liberation Edition

• Update to latest upstream Fenix
• Only(?) actual Android programmer we have @abhijitvalluri is back with at-the-bottom tab controls for bottom URL bar users and tab switcher favicons (https://github.com/interfect/fenix/pull/49)
• They also bring us searchable add-ons and the ability to pick your own add-on collection! No longer will I have to respond to the every whim of users! You can add your own add-ons yourself! (https://github.com/interfect/fenix/pull/50)
• Apply the liberate patch! The Adjust, Leanplum, and (all?) other telemetry is now stubbed out, and we don't ship the SDKs. The telemetry and experiment settings are also now all false by default, and the UI for them is gone. (You may need to do tricks to turn them off, like clearing app data, if you upgraded and they weren't off already and you still find telemetry being sent or yourself being experimented upon.) (https://github.com/interfect/fenix/issues/25)
• Spell "weasel" correctly. We're still in the market for a new, not-already-used name, but this one should be spelled right.