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
Modify core data test helper for new tests
Fixes to CD test helper and fixing other tests

- Removing the reset of PSes for now. With concurrent writes/reads it causes many Core data code 134030 errors

- All AccountTests, BlogJetpackTests, EditPostViewControllerTests run

- CoreDataConcurrencyTest runs individually fine, but in the suite it becomes polluted by data from other tests (due to temp removal of hard reset)
Fix up more tests, keep other tests on main context

- Change context creation in ContextManager to avoid using dispatch_once, as it prevents recreation. ‘check and create’ should be the equivalent as before.

- Add a choice of context to WPAccount removeDefaultWPAccount with the default being the background context. The test should use the main context.

- Known issues: account tests cause exceptions due to a performBlock: save from another test in conjunction with the persistent store recreation. Cocoa error 134030.
Remove WPAccount from main on tearDown
Fix ReaderTest and fix crash on merging contexts
Add reciprocal concurrency test and fixes

- Rename ContextManager method for consistency

- Lock account creation (performBlockAndWait: does not block main thread in a test)
Add specific test for object permanence
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issue/634-coredata-tests

Conflicts:
	WordPress/WordPress.xcodeproj/project.pbxproj
	WordPress/WordPressTest/AccountTest.m
	WordPress/WordPressTest/CoreDataTestHelper.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.
Fix tests from changes since merge
Fix up SettingsVCTest

- Manage Blogs was obsolete

- Prevent notifications on simulator (was causing the tests to fail, and should just be done anyways)
Fix account removal with some tests

Because we destroy the contexts and PSC between tests, we must not remove the default account with a context which is tied to the OLD PSC. The cached __defaultDotcomAccount prevents other assert tests from passing.