mod_oembed: Prevent crash in media tag when no oembed metadata is found.
(cherry picked from commit b25b6ef3be7234fe9df89fef4f0673fd522ee02b)
mod_oembed: Better error reporting and "fix all" button
(cherry picked from commit afbc3ee3714cb9e74ea38cb34e468964ff7e005a)
mod_oembed: Update NL translation
(cherry picked from commit 1f16dda1943bae3b0cb0066b3ae04443aa5bbb02)
mod_oembed: Repair the repair function
(cherry picked from commit 45fa19187219e3a59c4e9466fbf0f8fe2ec296cf)
mod_oembed: Fix setting media title when programmatically importing an oembed media item.

The title used to remain empty when a call like this was made:

    m_rsc:insert([{category, media}, {oembed_url, "http://www.youtube.com/watch?..."}], Context).

This is now fixed, the title is set when a new OEmbed URL is used and
the rsc does not yet have a title.
(cherry picked from commit 5d00089c97cb4f1e1baae8c81464dd3a45ba8099)