Gradle 3.x/4.x compatibility.

[axls]

This PR makes possible to use plugin with gradle 3.x/4.x.

[carlolf]

Sadly, I suppose Steffen has no time for merging your pull request; he effectivley did not update this project since 2015.

For people like us using Gradle on GWT projects nowadays(!), this is a very bad condition. I even thought about migrating our project to Maven; but I hate to do so.

If I had deeper knowledge of GWT and Gradle, I would fork this project and work on the fork. Is there anyone here interested in doing this?

[axls]

@carlolf I already have forked and patched version in my company's private nexus, and just thought to share this patch with community. By the way, there is another plugin - https://github.com/Putnami/putnami-gradle-plugin (I didn't try it). But it seems that this project is inactive too.

[carlolf]

@axls : I saw this Putnami Plugin, but it seems just to be a clone of this plugin here. Maybe you can publish your nexus version on Github. I sure would give it a try.

[jiakuan]

@axls @carlolf @steffenschaefer I found this plugin is quite useful for my GWT development, although there were no updates in latest two or three years.

I forked this repo here https://github.com/jiakuan/gwt-gradle-plugin and I plan to continue the maintenance of this project. I changed the group id to org.wisepersit so that I can publish Maven central.

I have upgraded Gradle to 4.0.1 and upgraded GWT to 2.8.1, including the changes in this pull request.

Additionally, I generated a nicer documentation site here: http://gwt-gradle-plugin.documentnode.io/

Please feel free to use the new version I created, and create new issues in my fork site when you see any issues.

[axls]

@jiakuan Great. I'll try it. Thank you.