Add phpunit/phpunit to require-dev section in composer.
Fix phpunit fail for testSqlTimeframe and testSqlTimeframeRequired: name of columns should be included in brackets [...].
Add option include_unpublished to behavior parameters: if it is false (by default), then behavior shows only published items. Else - all.
Update documentation.
Merge branch 'master' of github.com:smirik/PublishableBehavior