support Box videos

[ijlyttle]

example:

<iframe src="https://cloud.app.box.com/embed/s/yvslpsbq3rq1pqz0spqxr8sh62fe5hn9" width="708" height="458" frameborder="0" allowfullscreen="allowfullscreen" webkitallowfullscreen="webkitallowfullscreen" msallowfullscreen=""></iframe>

more generally:

<iframe src="https://{custom_domain}.app.box.com/embed/s/{shared link value}?view={list or icon}&sortColumn={name, date, or size}&sortDirection=ASC" width="{pixels}" height="{pixels}" frameborder="0" allowfullscreen webkitallowfullscreen msallowfullscreen></iframe>

The video embedded here:

https://app.box.com/s/m5do45hvzw32iv2aors3urf5pgkxxazx

references:

• https://developer.box.com/docs/box-embed#section-build-box-embed-programatically
• https://community.box.com/t5/Sharing-Content-with-Box/Create-a-Box-Embed-Widget/ta-p/19719

[ijlyttle]

This seems to suggest arguments:

id
custom_domain = NULL (check for an option)
width = 708
height = 458
frameborder = 0
allowfullscreen = TRUE