Change IBOutlets to weak

- For the ‘easy ones’

- Change the pattern of “init then add property” to “init with object”.

- WPAddCategoryVC property name change to get rid of ‘new’ reserved prefix
Clean up selection vcs

- WPSelectionVC and WPSegmentedSelectionVC look like they can be collapsed into one

- Weak references

- Don’t use initWithNibName

- Use properties
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issue/639-weak-views

In addition: EditPostViewController uses properties, more views to weak references, and some cleanup.

Related to #686 and #696

Conflicts:
	WordPress/Classes/EditPostViewController.m
	WordPress/Classes/EditPostViewController_Internal.h
	WordPress/Classes/MediaObjectViewController.m
Removes extended format bar. Removes list, code and toggle buttons.

Stubs an underline button.
Removes obsolete code.
Refs: #591
Deletes WPKeyboardToolbar as its no longer being used by anything.
Consolidate and remove WPKeyboardToolBarWithoutGradient.

Let's just have one keyboard toolbar class for now since only one is being used.
We'll rename WPKeyboardToolbarBase in subsquent commit.
Corrects format button heights when rotating from landscape to portrait.

Refs #591
Anticipates image for underline button.

Refs #591
Removes old references to removed formatting options.

Removes old stats keys.
Removes references in the post editor.
Refs #591.
Icons for formatting toolbar

Ref #591
Updates format bar with new icons.

Removes obsolete code related to sizing the buttons.
Cleans up some other code.
Refs #591
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/591-formatbar-refresh
Tinted images for highlighted states.

Refs #591
Tweaked reader list typography
Made Reader detail typography match list view
Merge branch 'develop' into issue/744-reader-detail-fixes

Conflicts:
	WordPress/Classes/ReaderPostView.m
Allow featured images to be tapped
Fix avatar not showing in Reader detail view
Fix multiple controllers getting pushed
Cleaned up layout code to fix height resizing