Moves reader comments into its own view controller.

Tapping on the comment icon on the post list or detail take you to the comment list.
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/2395-separate-comments

Conflicts:
	WordPress/Classes/ViewRelated/Reader/ReaderPostDetailViewController.m
	WordPress/WordPress.xcodeproj/project.pbxproj
Updating pods
Fix block declaration for changes made in the sync helper.
Let ReaderPostDetailViewController inherit from UIViewController

Removes dependency on UITableViewController.
Adds scrollview.
Simplifies constraints.
Replaces optimize switch with image size slider
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
Adds support for replying to a specific post.
Adds no results view. Switch to ReplyTextView.

Drops inline composer and comment publisher.
Adds the post header view.
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
Updates image optimizer to respect image sizes.

Removes replaced optimizer methods.
Removes section header. Adds border to post header.