nextcloud
set imageurl prefix to use new nextcloud-commons capabilities
This sets the url prefix in nextcloud-commons:markdown
It requires newhinton:feature/noid/imageurl, until a version with this pr is released, it is nessessary to add a local version of that branch to be used by the notes app.
This pr is tiny, and only supports images. The web-app does support arbitrary attachments, and provides a download for those. However, i think i broke mardown-conventions in doing so, so we may or may not want to support it here aswell. If we do want to support it, i have to change the library to make it work.
Also, when images cannot be loaded, we currently only show a broken image, shouldnt we also display the alt-text?
closes #1051
Oh, and i didnt check if servers that override index.php work, since the note object did not provide the "basepath", just the fqdn (or ip adress in my case)
Rebased due to major technical updates in terms of libraries, especially AGP and SSO
