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

Conflicts:
	WordPress/Classes/EditPostViewController.m
	WordPress/Classes/NotificationsCommentDetailViewController.m
	WordPress/Classes/WPInfoView.h
	WordPress/Classes/WPInfoView.xib
Merge pull request #740 from wordpress-mobile/issue/639-weak-views

#639 Make views weak [partial]