Before rendering a profile item in the aside, make sure there are images attached.
Fixes #61

* When assigning the featured profile, make sure there are images
associated with it
* When picking random profiles, make sure there are images associated
with each profile
* If there is no featured profile (because there were non images
associated with it), bring back 10 random profiles instead of 9
* If the preferred assigned image type (like small_thumb) isn't
available on a profile, backup to another assigned image type (like gallery)
Merge branch 'develop' of git://github.com/johnshopkins/machado into develop