Images / videos gallery dialog

[pawelgrzybek]

Videos and images gallery is a mess. There is so many things broken about it and the whole things needs a refactor. Some of the things that are wrong.

• images / videos reload the whole dialog instead of exchanging the content inside the dialog
• navigation buttons on the images carousel should preload resource on hover, or even always load the next /previous item
• captions under the images are strangely positioned, and this complicates the markup a lot
• naming convention and the reusability of these components looks like someone built it in 15 minutes and copied pasted bunch of stuff from somewhere else (this is precisely what i did)
• the content of the dialog and the shell of a dialog should be better separated, now they are very tightly coupled to gallery, but it is impossible to easily adapt the dialog to reuse it for something else