v1.9.5: Screen protection and backup changes

[Futsch1]

To protect the screen of the app from showing in the last viewed app dialogs and to add additional security against apps potentially reading the content of the screen of the app, a setting ("Block screen capture") was added to optionally protect the screen using an integrated Android mechanism.

The backup is now built in a modular way. When starting the backup, it can be selected which aspects of the app shall be included (medicine settings and/or reminder events). During restore, the app detects the contents automatically and only restores the respective portion.