[MNG-6838] Consider build identifiers in version order comparison

**[Elliotte Rusty Harold](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=elharo)** opened **[MNG-6838](https://issues.apache.org/jira/browse/MNG-6838?redirect=false)** and commented

Per semver:

Build metadata MAY be denoted by appending a plus sign and a series of dot separated identifiers immediately following the patch or pre-release version. Identifiers MUST comprise only ASCII alphanumerics and hyphen [0-9A-Za-z-]. Identifiers MUST NOT be empty. Build metadata MUST be ignored when determining version precedence. Thus two versions that differ only in the build metadata, have the same precedence. Examples: 1.0.0-alpha+001, 1.0.0+20130313144700, 1.0.0-beta+exp.sha.5114f85.

However, our spec doesn't mention the plus sign as having this special meaning. Should we do something about this? 

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No further details from [MNG-6838](https://issues.apache.org/jira/browse/MNG-6838?redirect=false)

No file, test, or entry point is named. Review Maven's version-order comparison and the linked MNG-6838 discussion against the cited semantic-versioning rules; done means reaching a decision about build metadata handling and aligning the specification, behavior, and tests with that decision.

Written by the indexing model from the issue text.