Add checkstyle to build #3928
Description
The recent Eclipse update changed the way that code formatting is applied. We could potentially use this plugin to automatically format the code from Maven rather than relying on Eclipse.
Unfortunately we also currently apply Eclipse cleanup save actions with the Maven plugin doesn't support.
If we apply checkstyle to the build we could enforce that the code style matches what would occur via the cleanup actions (adding this. etc). This would then allow us to use the Maven plugin to format the code.
As an added benefit checkstyle is also likely to help a lot when people contribute code.