multi-module build

[dwhjames]

The main aim here is to remove log4j and main
classes from compile scope in the core library.

This will help integrate ethereumj-core as a library
into projects that don’t choose to use log4j and
want to use a different logging framework to back
slf4j.

Problems encountered:
org.ethereum.util.AdvancedDeviceUtils uses log4j
to dynamically change the logging config. There was
no resolution other than to remove this.

update to gradle and wrapper script

[dwhjames]

@Nashatyrev, as discussed on
https://gitter.im/ethereum/ethereumj?at=5719093c98c544f1396d516a

Here’s my first attempt at this. I’m far from a Gradle expert—happy to hear suggestions for improvements.

[Nashatyrev]

Many thanks for this PR! I like this modular approach, though need to discuss with the team if we have any fallbacks here

[dwhjames]

I think there’s probably room for further improvement, but I got this far enough to accomplish my original goal of tidying up what was on the classpath for the core library.

[coveralls]

Coverage increased (+1.5%) to 58.316% when pulling bc6cdfb on gemini:topic/sub-projects into 2199165 on ethereum:develop.

[dwhjames]

Resolved the merge conflict in 30b78d4

[coveralls]

Coverage increased (+1.4%) to 58.346% when pulling 30b78d4 on gemini:topic/sub-projects into 33fcacb on ethereum:develop.

[Nashatyrev]

@romanman I believe you were going to comment on this PR

[Honestnode2]

Trying to master the Trivial pursuit of coding and creating an equal opportunity for all to access funds at time of need

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