Merge pull request #11 from luiges90/master

Make Attachment manager return Attachment object
Add CommentManager.
Pass request object to createComment method as create comment requrie IP and agnet.
Add comment manager service.
User ID type fix.
Add wp_find_comments_by_post.
PHPDoc bug fix.
Use BlogManager to obtain current blog entity manager in option manager.
Revert "Use BlogManager to obtain current blog entity manager in option manager."

This reverts commit 98892cb30df3cd7e5d792d7469fdd9424767e76a.
Update all entity manager service which switch blog.
Delete unused namespace.