Improved account deletion

- Removed old "WordPress.com" credential deletion. We've had accounts
  for a while
- Don't cancel/reset the API object if it's not initialized
Moved wp.com cookie deletion to AccountService

WordPressComApi should be only about REST.
AccountService should be handling self-hosted account removal and
clearing cookies for those as well, but that's another issue
Updated LocationServiceTimeoutDuration to 5 sec
Merge pull request #1860 from wordpress-mobile/issue/1859-tweak-location-services-timeout

Updated LocationServiceTimeoutDuration to 5 sec
Merge pull request #1858 from wordpress-mobile/issue/1842-keychain-sign-out

#1842 keychain sign out issues
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into feature/editor-update

* 'develop' of github.com:wordpress-mobile/WordPress-iOS:
  Updated LocationServiceTimeoutDuration to 5 sec
  Moved wp.com cookie deletion to AccountService
  Improved account deletion
Editor added UIAlertView+Blocks pod; navbar hide/show logic for editor