Improve error log message for duplicate UUID

We now output the path of the item which use the same UUID.
Remove use of deprecated method
Rework bundle update scheduling

We now store the time of last check in user defaults instead of via extended attributes on the source(s) and do a check every third hour, except of errors, where we retry after 30 minutes.

We now also check for bundle updates even if the sources hasn’t been updated. This is incase we previously updated a source but failed to then update bundles, these will now be updated when we retry, rather than next time the source index has updates.

Overall the code should be simpler and thus more robust. The text in the Bundles preferences page has also been improved slightly in that it will now tell the user if there was a problem updating the bundles, although for the specifics, the user will need to grab the log.
Make s/w update status text resizable