Import external attachments

Makes local copies of all the linked images and pdfs in a post, adding them as gallery attachments.

Source & support:

https://github.com/ryanpcmcquen/import-external-attachments

Credits

This plugin is based on the work done in the “Import External Images” plugin by MartyThornley.

https://github.com/MartyThornley

HTTPS support added by IvanDoomer:
https://github.com/IvanDoomer

PDF support added by bengreeley:
https://github.com/bengreeley

Most of the JavaScript was rewritten from the original plugin, to reduce the
number of global variables.