This PR contains all the work that's gone in to the Autocomplete Improvements Milestone, it is paired with a corresponding schema update.

The PR is focused around fixing bugs and flaky behavior in /v1/autocomplete that's been reported by our users, I've also taken the opportunity to triage all the incoming requests for autocomplete, clean up some messy parts and add more code coverage.

The major difference in behavior is due to how we handle analysis and especially synonym substitution for autocomplete, an example of a query which was not previously possible using phrase matching:

improved analysis

/v1/autocomplete?text=vic uni wellington

1)  Victoria University of Wellington, New Zealand
...

more information about the analysis changes can be found in: pelias/schema#105

final token is a stopword bug

This reported bug has been squashed: pelias/pelias#211

/v1/autocomplete?text=green lane

 1) Green Lane, PA, USA
 2) Green Lane Farms, Lower Allen, PA, USA
...

improved server-side tokenizer

Improved parsing of source data containing commas or slashes as delimiters, such as in Bedell Street/133rd Avenue. see: pelias/schema#113

improved client-side tokenizer

In order to generated the best/most efficient queries possible, we've added a client-size tokenizer which mimics the functionality of the server-side tokenizer. see: #529

improved handling of ordinals

This allows users to partially type an address such as "33rd street" as "33r", see pelias/schema#96

improved admin matching, particularly for non-delimited queries

this PR also includes a fix for parent.borough not being targeted during admin patching. see #527

/v1/autocomplete?text=200 dean st brooklyn

 1) 200 Dean Street, Brooklyn, New York, NY, USA

indexing of single digit numbers

in the past we did not index single digit numbers, they are now present in the index without causing a major increase in disk/ram usage.

/v1/autocomplete?text=grolmanstr 8

1)  Grolmanstr. 8, Köln, Germany
...

tighter 'focus' clustering and improved localized matching

see: http://missinglink.embed.s3.amazonaws.com/pelias_clustering.png

house number can be provided in 1,2 or 3rd position

mainly for for Germanic addresses schemes. see #489

/v1/autocomplete?text=wilmersdorfer str 51

1)  Wilmersdorfer Straße 51, Kiel, Germany
...

boosting of exact matches

an additional query segment was added to ensure that outputs that more closely match the input text appear higher than those which only partially match.