This should be supported both in the administrative File Cabinet view as well as the CKEditor popup view. Drag in files, it uploads, and then presents you with a page where you can set "title" and "alt" on all of them, and then once you've done that they are saved.
Recommended but not tested, this looks like a pretty good jQuery plugin for doing this: https://github.com/ProgerXP/FileDrop
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