Move all the public static stuff into a configuration & data storage

.../java/info/nightscout/android/medtronic/MainActivity.java

.../android/medtronic/message/PumpStatusResponseMessage.java

...t/android/medtronic/service/MedtronicCnlAlarmManager.java

.../android/medtronic/service/MedtronicCnlIntentService.java

...roid/upload/nightscout/NightscoutUploadIntentService.java

...ava/info/nightscout/android/utils/ConfigurationStore.java

...rc/main/java/info/nightscout/android/utils/DataStore.java

...cout/android/xdrip_plus/XDripPlusUploadIntentService.java