Remove partial output on startup
Use connect-mongo instead of connect-mongodb

The former package isn't maintained anymore and prints a warning on
startup.
Show messages on /
Implement DELETE /scores/:id
Add deletion button to the score view
Add confirmation step for deletion
Add some message helper functions

Currently only used for racks, should be extended to scores.
Add DELETE /racks/:id
Add a deletion button to the rack view
Fix Rack.findByScoreId finding invalid racks

Without $elemMatch the $lte and $gte queries might match on different
array elements which is obviously not wanted here.
Merge branch 'delete'
Use message helpers for scores
Add search form to the results page