Ignore remote orgs in CKAN harvester

If #17 progresses we can do somethign similar for them, although it amy
be more complicated because of authorization issues.
[#34] Fix harvest_source_clear action

Some typos in the SQL statements, and also the source needs to be
reindexed to update the status with the counts.
[#34] Expose harvest source clear button
[#34] Allow all authorized users for a source to clear it