Remove JUnitReportTestRunner
Add findbugs to Gradle build
Add checkstyle to tests-on-jvm project
Add support for recording code coverage
Update build tools version for subprojects
Add support for code coverage to tests-on-jvm project
Reformat according to style
Tighten types in Folder#fetch(…)
Fix some warnings in ImapStore / Pop3Store / WebDavStore
Move TracingPowerManager into mail package
Move into plugin
Move mail tests into plugin