I couldn’t reproduce #530, but I think some of these changes should help:

 * Removed the blog object from the post model, instead just use post.getBlogID to build the blog object when we need it.
 * Ensure we have a valid blog object in PostUploadService before attempting to upload the post.
 * use notNullStr() on getMaxImageWidth() in the blog model.

I also noticed that we were unnecessarily storing an ID to remember the spinner selection for the max image width. We can just use the Adapter’s getPosition() for that so I deprecated it.
Merge pull request #535 from wordpress-mobile/issue/530-post-upload-service-crash

Potential fixes for #530