Fixes #80:
 * Create default 'Table' visualization for all queries
 * remove 'Table' type when creating new visualization
 * Set type as the default visualization name (instead of the query name)
 * Remove description field and advanced mode
 * Remove section for adding new visualization in new widget dialog
fix issue where start_workers failed when settings.CONNECTION_ADAPTER does not exist
Merge pull request #83 from EverythingMe/viz

Visualization Followups + workers bugfix