Incremental Field Updates through Stacked Segments [LUCENE-4258]

Shai and I would like to start working on the proposal to Incremental Field Updates outlined here (http://markmail.org/message/zhrdxxpfk6qvdaex).

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Migrated from [LUCENE-4258](https://issues.apache.org/jira/browse/LUCENE-4258) by Sivan Yogev, 14 votes, updated Jul 01 2014
Attachments: [IncrementalFieldUpdates.odp](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/IncrementalFieldUpdates.odp), [LUCENE-4258.branch.1.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch.1.patch), [LUCENE-4258.branch.2.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch.2.patch), [LUCENE-4258.branch.4.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch.4.patch), [LUCENE-4258.branch.5.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch.5.patch), [LUCENE-4258.branch.6.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch.6.patch) (versions: 2), [LUCENE-4258.branch3.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.branch3.patch), [LUCENE-4258.r1410593.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1410593.patch), [LUCENE-4258.r1412262.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1412262.patch), [LUCENE-4258.r1416438.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1416438.patch), [LUCENE-4258.r1416617.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1416617.patch), [LUCENE-4258.r1422495.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1422495.patch), [LUCENE-4258.r1423010.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258.r1423010.patch), [LUCENE-4258-API-changes.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4258/LUCENE-4258-API-changes.patch)
Linked issues:
- #5341
- #4910

Start by reading the IncrementalFieldUpdates.odp proposal and the attached LUCENE-4258 patches, then inspect linked issues #5341 and #4910. The issue does not specify files, tests, or a completion criterion, so confirm the intended design and current status before making changes.

Written by the indexing model from the issue text.