Added Media icons
Merge remote-tracking branch 'origin/dev' into edo
Added OSU logo and changed some code for media linking
Added some media linking work and working on greying out empty definition segments
Added labels to sidebar images and organized code/ added comments (GrossIndexViewController.m omitted)
GrossIndexViewController with labelled sidebar and comments
Neuro Index Video Media Button Action work-in-progress
Empty definitions  in segmented control are now grayed out and unclickable
Added Spinal Tracts page
Histo words
Gross Anatomy annotations switch should now change image.  Also added annotations label
Buttons are disabled when annotations are not shown.
Merge remote-tracking branch 'origin/dev' into sdm
Embryo Index duplicate button defining correction
Added sidebar to Histo Slide 1 pag (and commented out sidebar to Neuro Tracts), UI revisions
Working gross 2-D media button
Working embryo video media button
zooming for images
fix zoom
embry zoom adjusted