Issue #22 Allow non-root linking of images
issue #24 - hide "remove image" when no image.
issue #25 = show image when editing
issue #21 - comment dates formatted for humans.
issue #27 - send access level on image change
address issue #23 for existing comments

submit new image on button press, not on image add
address issue #23 for new comments

Submit image on button press
minor code cleanup
Merge pull request #29 from azavea/topic/commentFixup

Topic/comment fixup