Please add setter for “reuseStrategy” property of org.apache.lucene.analysis.Analyzer class, since its breaking my implementation that I used to achieve using Lucene 2.9 APIs [LUCENE-6324]

Please add setter for following “reuseStrategy” property of org.apache.lucene.analysis.Analyzer class, since its breaking my implementation that I used to achieve using Lucene 2.9 APIs:

private final ReuseStrategy reuseStrategy;

basically my reuse strategy is depending on external configuration, and i need to reset the strategy in the analyzer whenever configuration is changed.

PS: I'm working on a project to migrate the code that is using lucene 2.9 to new implementation using lucene 4.9.

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Migrated from [LUCENE-6324](https://issues.apache.org/jira/browse/LUCENE-6324) by Sekhar, updated Jun 10 2015
Environment:
```
Windows/Linux and JDK 7/8
```

Start with org.apache.lucene.analysis.Analyzer and inspect the private reuseStrategy field and its surrounding API. Verify how an externally configured ReuseStrategy should be replaced after configuration changes, and consider the existing Lucene 4.9 API expectations; the work is done when callers can reset that strategy through the requested setter.

Written by the indexing model from the issue text.