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.
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.
Removes section header. Adds border to post header.
Style tweaks. Fixes call to send reply.
Fix border layout. Better tap gesture behavior.
Show new reply in list once its saved.

Adds new methods to comment service.
Tweaks the way comment pages are calculated to make sure we can try to refetch a partial page.
Remove obsolete classes.
Different placholders when replyint to post vs comment

Also fixes an issue the selection state would be lost on rotation.
minor code style correction.
Optimistically save replies in the reader.
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/2395-separate-comments

Conflicts:
	WordPress/Classes/ViewRelated/Reader/ReaderPostsViewController.m
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/2395-separate-comments
Minor refactor.

Avoids calling avatar methods if the hash is nil.
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/2395-separate-comments

Conflicts:
	WordPress/WordPress.xcodeproj/project.pbxproj