Migrate code to Swift

[LEOYoon-Tsaw]

• Migrated code base to pure Swift, no more Obj-C (except for a bridging head), no more xib
  • Only 2400 lines of Swift code after migration
• No major feature change is expected, if any, leave an issue
• Limited updates:
  • Disabled Sandbox, as it complicates users syncing file
  • Added a menu item for logs folder
  • updated candidate_format to [index]. [candidate] [comment] for flexibility and better readability
  • updated squirrel.yaml version to 1.0 and added new options that are recently added
  • horizontal: true/false is further deprecated, users should not use it anymore
  • labels will vertically center if label font is smaller than candidate font, better matches macOS builtin IME
• Improvements:
  • Fixed a bug that when using non-inline preedit, the first candidate may have too large a space above it in linear layout
  • Address #853 by dynamically add plugins to xcodeproj
  • --enable-input-source, --disable-input-source and --select-input-source may take extra args to specify a method
  • Adopts Sparkle EdDSA

[lotem]

I don't get how the sandbox benefits. It seems only harder to locate files.

[LEOYoon-Tsaw]

I don't get how the sandbox benefits. It seems only harder to locate files.

It restricts unintentional changes to files. There's lua, it's possible that a user accidentally delete files by misusing lua script.

It also gives users confidence, that Squirrel will not touch anything else than clearly stated in entitlement. Users don't have to trust us not being evil.

But it makes "sync user data" almost impossible without a UI overhaul. So will have to leave it for future reconsideration