3.0 final release

Application is configured to target Android 8.0 (API level 26)
Android project have been ported to Android Studio 3.2 and Gradle 4.6 (Android Gradle plugin 3.2.1)
Added new uFR Plus devices descriptions to res/xml/dev_desc_filter.xml
Updated DlReader lib sub-module to 2.9

Generated signed app/release/app-release.apk