Set back button correctly for navigation bar
Add in title to Add Category screen.
Fixed font for "Parent Category" on add category screen.
Remove "Themes" item from BlogDetailsViewController.
Changed "Image Quality" text to "Image Dimensions".
Added tracking for multiple people properties per mixpanel 'event'.
Added metrics on last time users performed certain actions.

Added in Mixpanel People Properties to track:
- Last Time Accessed Reader
- Last Time Accessed Theme Browser
- Last Time Liked Article
- Last Time Reblogged Article
- Last Time Loaded Freshly Pressed
- Last Time Commented on an Article
- Last Time Stats Accessed
- Last Time Published Post
- Last Time Notifications Accessed
- Last Time Shared item
Adding in Mixpanel "$created" property.
Adjusted when we increment 'Application Opened' people property.
Renaming method in WPAnalyticsTrackerMixpanel to be more obj-cish.
Renaming another method to be more objc-ish.
Fixes issue #1590 crash when selecting Published On for a Page
Merge pull request #1586 from wordpress-mobile/issue/add-date-people-properties

Add in people properties to track last time users performed key actions
Merge pull request #1587 from wordpress-mobile/issue/adjust-mixpanel-initialization

Adjusted when we increment 'Application Opened' people property.
Merge pull request #1582 from wordpress-mobile/issue/1366-change-image-quality-text-to-image-dimensions

Changed "Image Quality" text to "Image Dimensions".
Merge pull request #1579 from wordpress-mobile/issue/1492-fix-font-in-add-category-screen

Fixed font for "Parent Category" on add category screen.
Merge pull request #1578 from wordpress-mobile/issue/1493-add-title-to-add-category

Add in title to Add Category screen.
Merge branch 'issue/1495-post-editor-back-button' of https://github.com/keegnotrub/WordPress-iOS into keegnotrub-issue/1495-post-editor-back-button

Conflicts:
	WordPress/Classes/EditPostViewController.m
Merge pull request #1581 from wordpress-mobile/issue/1580-remove-ability-to-browse-and-select-themes

Remove "Themes" item from BlogDetailsViewController.
Updating version numbers to 4.0.3 (from 4.1)