Allow for an Image Gallery with 1 column

[husobj]

When you upload multiple images to a post you can insert a gallery from the media popup. However, it doesn't give you an option to insert a gallery that is only one column wide.

I often want to easily insert all the images in a single column and I would guess that other people may want to do this too - particularly for a photoblog style site, I've certainly visited many sites that display many images one after another. As there is no option in the media popup to insert a single column I imagine many people insert each image manually.

However, the gallery shortcode does handle columns="1" as a parameter but the select menu in the media popup does not give 1 as an option. Would it make sense to often 1 column as an option?

[greenshady]

I get questions about how to make single-column galleries from theme users all the time and point out that they should use [gallery columns="1"]. I never knew the select box didn't have an option for it.

Makes sense to me, and it's a simple patch.

[husobj]

Yes, seems like a bit of an oversight that 1 column was omitted from the menu.

[nacin]

(In [16449]) Include a single-column option in gallery settings. props husobj, fixes #14836.