Android Studio wants to ignore gradle.properties, so store release properties in release.properties.

- Update Fabric to latest

Add “Check for App Update” menu item.
Don’t render trend arrows using HTML - use Unicode instead.
Rename app from “NS 600 Series Uploader” to “600 Series Uploader”.
Experiment with adding status tiles.

Upgrade to Gradle 3.3, Build Tools 25.0.2, Realm 3.1.2
Remove duplicate MedtronicCnlAlarmReceiver
Fix crash when viewing Registered Devices after package updates.

03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err: org.json.JSONException: No value for batteryLevel
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at org.json.JSONObject.get(JSONObject.java:389)
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at org.json.JSONObject.getDouble(JSONObject.java:444)
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.a.a.c.b.a(Unknown Source)
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.a.a.c.b.b(Unknown Source)
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.a.a.c.a.a(Unknown Source)
03-30 18:06:04.489 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.d.a.c(Unknown Source)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.a.k.a.c.d.a(Unknown Source)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at com.bugfender.sdk.a.a.k.a.c.d.call(Unknown Source)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
03-30 18:06:04.490 10335-10397/info.nightscout.android W/System.err:     at java.lang.Thread.run(Thread.java:818)

Fix graphing
Fix for Realm hard crash

A few small changes that catch rare errors with the CNL specially when signal is weak.

- minor changes

- add git hash to VersionName to have more details

Fix #52 (Thanks @rahim).
Updated to support latest Android studio.

- Add splash screen
- Refactor UI
- Remove logback
- Add Bugfender for remote logging/debugging
- Use Realm.io for locally storing data
- Don't require an Internet connection to poll and store data locally
- Improve setup flow
- Add the beginnings of a Status activity
- Change device poll and upload tasks to be IntentServices

- Refactor UI (use Material Design and new font, drop to single style.xml)
- Do the pump comms using an IntentService in a separate thread
- Add extra OTG check
- General clean up and refactoring (improve naming and code).

Code cleanup and minor refactoring to improve maintainability and the ability to internationalise the app.
Fixes #43

Fix #6

Remove hardcoded keys.