Add tvOS release package

[zgramana]

See #918

[snej]

Dependent on #1042 — I forgot I hadn't merged the tvOS build support in the Xcode project into release/1.1 or master.

[zgramana]

Did you meant release/1.2 above?

[snej]

Yeah.

Some build notes for Michael, since I ended up using a different/better approach than what I did for the 1.1.1-appletv branch:

• There aren't any new targets for tvOS. Instead, the iOS targets can now build tvOS too. You just need to use the -destination flag to xcodebuild to specify which platform to build for.
• Build output will be in Release-iOS-universal as usual, or Release-tvOS-universal for tvOS.
• There's a chance the capitalization is different in those directory names, since I ended up changing a lot of the configuration behind them ... if you get file-not-found errors on the build bot, take a look at the case.

[michaelkwok]

I will update the build script for this. Couple questions before I make the changes.

1. With this change, I take it we don't need to do any copying of libCBLForestDBStorage.a since it's no longer generating Release-CBLForestDBStorage-ios-universal
2. Do we still need to create 2 packages for iOS vs tvOS for release?

[snej]

libCBLForestDBStorage.a is in Release-iOS-universal.

Yes, we probably want a separate package/zip for tvOS.

[michaelkwok]

Great, thanks!

[michaelkwok]

Actually, what I meant to say was that "libCBLForestDBStorage.a is in Release-iOS-universal" now, we probably don't need to copy into "Release-iOS-universal/Extras" like we did before this change. Let me know if I still need to copy or move it under Extras?

[snej]

In the zip archive it should be at top-level, next to the .framework, not in the Extras folder. Thanks!

[michaelkwok]

I have added tvOS to release/1.2.0 and master branch.