Change neo4j-community packaging from jar to pom.
Turn PageCache.unmap into PagedFile.close
Fix a couple of warnings in PageCacheTest
Fix page cache bug where write cursors racing with PagedFile.close can prevent dirty pages from being flushed to storage
EncodingIdMapper: At least one processor.
Merge pull request #3719 from martinfurmanski/2.2-encoding-id-mapper-min-proc

EncodingIdMapper: At least one processor.
Supports multiple disjoint id spaces within the same IdMapper

Each id given to IdMapper is accompanied a Group with an id. Looking up a
value in the IdMapper requires to pass a predicate for matching ids.

Currently this functionality isn't yet used by Input implementations, but
that can be viewed as a separate concern, where this commit is just for
enabling the feature.
Merge pull request #3709 from nawroth/neo4j-community-pomfix

Change neo4j-community packaging from jar to pom.
Merge pull request #3703 from chrisvest/2.2-unmap-to-close

Turn PageCache.unmap into PagedFile.close
Merge pull request #3686 from tinwelint/2.2-disjoint-id-spaces

Supports multiple disjoint id spaces within the same IdMapper