Replace joda time with JSR-310 implementation

[friedger]

E.g. https://github.com/JakeWharton/ThreeTenABP or later Java8 implementation

[tasomaniac]

I would put priority low to this. We have a lot to do and JodaTime works for us. The work to do this is huge

[seventhmoon]

Java8 java.time is not included in Android. Jake's port is an alternative. However, I also see no reason for a change at this moment.