v4.0.0_Alpha1

Faster app backup & restore
- New backup format with faster compression and encryption of your app backups should cut down your backup & restore time by at least 20%-40% on most devices.

- Important: Backups taken with v4.x cannot be restored with previous versions of Swift Backup. Backups taken with previous versions are of course supported.

Sign-in without an account with limited features
- Users can now choose to sign-in anonymously, offline, without a Google account. This feature is added for users who only want to use Swift Backup for local backups without any premium features. Cloud backups or premium features cannot be used without Google sign-in.

- Swift Backup settings, lists of Favorite apps, Blacklisted apps are saved locally for anonymous users in 'SwiftBackup' folder and will be restored from here during sign-in.

- Note that backups taken with anonymous sign-in are encrypted with common encryption keys as opposed to users with Google sign-in where encryption keys are unique for each user. Also, backups taken with anonymous sign-in cannot be used with accounts with Google sign-in and vice-versa.

Other changes
- Apps: Much faster loading of apps list
- Apps: Improved checks for app data changes
- Swift Backup APKs are now saved in 'SwiftBackup' folder
- Other minor UX improvements and fixes