Fix spatialmatch relev handling case where feature may overwrite itself with a more poorly scored result.
Caching optimization for coalescezoom + spatialmatch.
Cleanup.
Add (failing) test for #181.
Fixture update.
Merge branch 'test-relev-fix' into relev-fix
Merge pull request #181 from mapbox/relev-fix

spatialmatch relev fix