All comments should be addressed adequately.

This patch allows previewjobs to take a URL in case they understand how to deal with that. preview plugis can specify a list of protocols which they support, this is then matched with the scheme of the URL and if supported the URL is passed directly into the plugin. Otherwise, the file is downloaded and passed as local file (this part hasn't changed).

A suitable preview plugin that does the job will be submitted separately to kde-runtime.

Is this definitively Frameworks 5 material, or would you be OK with adding it to the 4.7 branch? (The latter would mean, we could use vanilla kdelibs for Plasma Active 2 in december.)

Generating preview for HTTP URLs, for local files and for remote files without a suitable plugin.