Revert "IDEAPLUGIN-6 updated release notes and changed ContaingMethodCellRenderer to only place a visual indication on events that are handled in the same class."

This reverts commit 6218fa4e25acb66d0b9b24b451483be2606156d2.
IDEAPLUGIN-6 updated release notes
IDEAPLUGIN-6 added new icons and there is now a visual distinction in the dropdown of an event publisher between sagaevents, internalevents and plain events
[maven-release-plugin] prepare release axonframework.intellij.ide-0.3.1
[maven-release-plugin] prepare for next development iteration