work with precisions 1..9 based on the zoom levels
using precision levels 1..5 only
fixing valid query test
test precision (and while writing the test, caught/fixed the bug where zoom=4 ftw)
better naming
updating getPrecision() to handle null/undefined/empty zoom params
Merge branch 'master' of github.com:pelias/api into precision
Merge pull request #24 from pelias/precision

work with precisions 1..5 based on the zoom levels