Change table_size to use pg_table_size()

Change table_size to use pg_table_size()

Change table_size to use pg_table_size(), i.e. to include the TOAST
table size in the numbers reported. Add new actions indexes_size and
total_relation_size, using the respective pg_indexes_size() and
pg_total_relation_size() functions. All size checks will now also check
materialized views where applicable.

Close: #32, #83