Replace Joda time with Joda Time Android
Using unbundled play services to reduce the number of methods and stay below the 65k limit.
Merge pull request #119 from nightscout/kl.jodatimeandroid

Replace Joda time with Joda Time Android
Merge pull request #120 from nightscout/kl.unbundlingplay

Using unbundled play services
Migrating ReadData to the core module
Moved to slf4j-style formatting
Merge branch 'dev' into 76-kl.mqtt

Conflicts:
	app/src/main/AndroidManifest.xml
	app/src/main/java/com/nightscout/android/Nightscout.java
Merge branch 'kl.readdatatocore' into 76-kl.mqtt-merge

Conflicts:
	app/src/main/java/com/nightscout/android/USB/CommonUsbSerialDriver.java
	app/src/main/java/com/nightscout/android/USB/USBPower.java
	app/src/main/java/com/nightscout/android/USB/UsbSerialDriver.java
	app/src/main/java/com/nightscout/android/USB/UsbSerialProber.java
	app/src/main/java/com/nightscout/android/dexcom/SyncingService.java
	app/src/test/java/com/nightscout/android/dexcom/ReadDataTest.java
	core/src/main/java/com/nightscout/core/drivers/ReadData.java
Cleaning up the merge