Catch an IndexOutOfBoundsException when creating the copy of the post content's editable. If the exception is caught we'll just use the post content EditText's current editable. Only drawback to this is that there's a quick flash of HTML displayed as the post is saving.

Also cleaned up a few compiler warnings.
Merge pull request #810 from wordpress-mobile/issue/797-post-save-out-of-index

Catch an IndexOutOfBoundsException when saving post content.