Colorbox improvements

[jasuarez]

A couple of minor improvements for colorbox theme:

• Show video title instead of video filename when opening a video.
• As it is done for albums, lets write below each media its title.

[saimn]

I have tested this, the idea is fine but when some images have a title and other don't this introduce a gap between images. To solve this one could use the height of images, but I'm not sure of the best way to do this. I will look if I find some time.

[jasuarez]

I've managed to reproduce the same issue, but in a different way: having different lengths in the title can also raise the problem.

[jasuarez]

Rebased PR against latest master

[saimn]

Hi @jasuarez ,

• About the title instead of filename, I think it was changed in b88d10a
• For the title below media, do you see a solution to avoid breaking the layout ? Thanks to add size property into Image object containing width and height of each image (thumbnail, big). #164, the size of the images is now available in the images properties.