database: couple of minor improvements

They are:
 * total inserts
 * measure processing time of each statement
 * start transaction on insert
runner: save time stats from db process
scheduler: couple of minor changes

They are:
 * [impr] show task and its priority in log
 * [bug ] fixed access to queue that is not created yet
 * [bug ] filter 'sort' section (fixes runtime error with '-t')