Make "Save Draft" on leaving the editor actually save a draft

git-svn-id: https://ios.svn.wordpress.org/trunk@4018 7d847f7c-ffe1-4a24-85be-b788d016d96a
Added new WPFLogMethodParam helper function

git-svn-id: https://ios.svn.wordpress.org/trunk@4019 7d847f7c-ffe1-4a24-85be-b788d016d96a
Better post previews

* Added autosave logic, so unpublished posts can get autosaved remotely
* If online, autosave drafts and show a real preview
* If the post is already published or we're offline, keep showing the simple preview

git-svn-id: https://ios.svn.wordpress.org/trunk@4020 7d847f7c-ffe1-4a24-85be-b788d016d96a
Implement better previews for pages

git-svn-id: https://ios.svn.wordpress.org/trunk@4021 7d847f7c-ffe1-4a24-85be-b788d016d96a
Refactor simple previews loading

git-svn-id: https://ios.svn.wordpress.org/trunk@4022 7d847f7c-ffe1-4a24-85be-b788d016d96a
Implemented remote autosaves

A post will be autosaved:

* Every 20 characters changed or so
* When you stop typing for 5 seconds
* When you tap on preview

Known issues:

* The "Discard/Save" alert when the Cancel button is tapped is shown even if the post is fully autosaved
* If you start a new post and it autosaves, choosing the "Discard" option only discards the changes since the last autosave

git-svn-id: https://ios.svn.wordpress.org/trunk@4023 7d847f7c-ffe1-4a24-85be-b788d016d96a
Reverted unused core data model version

git-svn-id: https://ios.svn.wordpress.org/trunk@4024 7d847f7c-ffe1-4a24-85be-b788d016d96a
Refactor autosave interval into a constant for easy tweaking

git-svn-id: https://ios.svn.wordpress.org/trunk@4025 7d847f7c-ffe1-4a24-85be-b788d016d96a
Less aggressive autosave values when using 3G

git-svn-id: https://ios.svn.wordpress.org/trunk@4026 7d847f7c-ffe1-4a24-85be-b788d016d96a
Show the WPToast when the user moderates a comment in the CommentDetailsView. Show an UIActivityIndicatorView in the cell in NotificationsScreen till the network opertion is fully completed.

git-svn-id: https://ios.svn.wordpress.org/trunk@4027 7d847f7c-ffe1-4a24-85be-b788d016d96a
Refactor cancel button alerts to handle autosaves better