Fetch post for comments if it's not set yet and show a header containing an overview of the post it belongs to in the new comment page
Merge remote-tracking branch 'origin/develop' into issue/2528-comment-page-header

Conflicts:
	WordPress/WordPress.xcodeproj/project.pbxproj
Merge remote-tracking branch 'origin/develop' into issue/2528-comment-page-header
Small bug fixes (introduced in the last commit for adding comment page header) related to getting a single post from server
Don't call weakSelf.managedObjectContext, since some reason it doesn't work
Remove extra space between cells in comment page caused by the footer height
When the post details are tapped in comment page, open the reader post detail page
Per koke's suggestion, fetching post for comment removed from Comment domain and moved to CommentViewController
Extra imports removed from Comment.m
Merge remote-tracking branch 'origin/develop' into issue/2528-comment-page-header
Use self instead of weakSelf in getPostWithID in PostService
authorAvatarUrl moved to BasePost from Post & ReaderPost
When a post or comment is updated associate to each other
In comment page when setting up layout cells don't download the gravatar
In comment page fallback to webview for post details (for self-hosted sites)
In comment page, strip html from post and comment content
Associating post for comments moved to PostService (koke's diff)
Only open reader from comment page if it's a dotCom blog
In comment page header show title and if it's empty show content snippet
Comment header and content shows the right info now - CommentView deleted