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
Merge pull request #121 from nightscout/kl.readdatatocore

Migrating ReadData to the core module
Merge branch 'dev' into kl.deviceabstraction