Tweak grid in order to use the store's autoSync option

By default the Ext JS store calls the get_data endpoint. To use the
autoSync option, the sync event gets cancelled and calls the onApply
method instead.
Fix for SearchPanel field names
Merge pull request #94 from scho/grid_auto_sync

Tweak grid in order to use the store's autoSync option
Merge remote-tracking branch 'upstream/master'