Reusable WordPress functions to be installed in your theme's functions.php. In order...

• Remove width and height attributes from <img>s uploaded in the Media Uploader. This does not work retroactively on already uploaded images.
• Remove devicepx which is added by Jetpack which adds back width and height attributes on <img>s inline. Only use this if you're using Jetpack.
• Add custom CSS for non-admin users to WP Admin, useful for hiding stuff you don't want clients to see.
• Add a box to the WP Admin Dashboard page, useful for displaying any information your clients might need to see. I generally use this to link to "how to WordPress" guides and tech support information.
• Set sensible default options for the Media Uploader when a user embeds attachments. Use the full-size image URL, no alignment, and won't wrap it in a link.
• Hide the WordPress logo on the WP Admin login page. (I'd like to add more code to minimize the amount of WordPress branding elements on each page at some point.)

• I would like to prevent a user-created image caption from having a height attribute but couldn't find a function to do it. I currently override it in CSS: .wp-caption { max-width: auto; height: auto; }