Applying spotless groovy support on groovy file format checks.

[fvgh]

Overview

Replaces custom formatting config for Groovy source files by GrEclipse formatting.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes
• All continuous integration builds pass

[fvgh]

Please have a look at the proposal for #843.
The configuration is provided as Eclipse prefs. If you prefer different file format (xml, properties, ...) let me know.
I adapted the config to match the current groovy code (allowing lists initialization to be 140 characters long).

If you are interested, I can provide another PR applying the GrEclipse to the gradle files.

[fvgh]

Sorry, my M2 proxy concealed the problem Traivs ran into. It seems that I still need a better understanding of a change introduced in spotless. Need to postpone this PR.