add comment field to changelog table
save comment from content entry
Making Tags behave a bit more like other Taxonomies. Fixes #1283
Merge pull request #1289 from tonicospinelli/changelog-comment

Changelog Note
Merge branch 'master' into feature/bolt2

Conflicts:
	app/view/_sub_changelogdetails.twig
	app/view/_sub_lastmodified.twig
	app/view/editcontent.twig