Basically when a page is viewed that has a blocktype of externalvideo
and doesn't have a type set, then call process_url and save the config
again.

This could be done as an upgrade path, but would mean a slow upgrade.
This patch does it on a on-view basis, and only does it the first time
the page is viewed

Bug #819079

Change-Id: If26ee3beaf01ebc1648542e4b5a49f645c893414
Signed-off-by: Hugh Davenport <hugh@catalyst.net.nz>