Add some Gems for profiling performance while in dev mode.
Add Bullet instrumentation to detect n+1 queries in development mode.
Use runnable.offerings_count (cached counter) instead of runnables.offerings.count
Do some eager loading of material elements we are going to need in collection views.
Add some DB indexes
WIP: undo this → only a temp change!  (if you see this on github, yell at me!)