RFR: 8264859: Implement Context-Specific Deserialization Filters [v7]

[Roger Riggs]

> JEP 415: Context-specific Deserialization Filters extends the deserialization filtering mechanisms with more flexible and customizable protections against malicious deserialization.  See JEP 415: https://openjdk.java.net/jeps/415.
> The `java.io.ObjectInputFilter` and `java.io.ObjectInputStream` classes are extended with additional
> configuration mechanisms and filter utilities.
> 
> javadoc for `ObjectInputFilter`, `ObjectInputFilter.Config`, and `ObjectInputStream`:
>     http://cr.openjdk.java.net/~rriggs/filter-factory/java.base/java/io/ObjectInputFilter.html

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Move merge and rejectUndecidedClass methods to OIF.Config
  As default methods on OIF, their implementations were not concrete and not trustable

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3996/files
  - new: https://git.openjdk.java.net/jdk/pull/3996/files/f1a797a5..141bf720

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3996&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3996&range=05-06

  Stats: 459 lines in 3 files changed: 232 ins; 141 del; 86 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3996.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3996/head:pull/3996

PR: https://git.openjdk.java.net/jdk/pull/3996