[#4] Changes in schema to accommodate organizations

Basically handle the 'owner_org' field in form_to_db and db_to_form.
Added 'owner_org', 'frequency' (has default) and 'config' to surplus
keys in check_data_dict.
Also remove schema tweaks to let package_show call the appropiate schema
function.
Update HarvesterBase

This is a convenience class that other harvesters can extend. Updates
include a cleanup of old functions and porting of enhancements from the
spatial harvesters.
Remove unnecessary extra quotes (see #381 on CKAN core)
add return True to import stage of ckanharvester

Was causing queue.py to report that the import had errored.
Merge pull request #9 from joetsoi/2.0-dataset-sources

add return True to import stage of ckanharvester
Merge branch '2.0-dataset-sources' into 7-harvest-source-templates