Add documentation about Java Logger for Error Handling

[MitchellDumovic]

This PR follows from discussion on #1419.

This is intended to be a an "implementation" of open-telemetry/opentelemetry-specification#696

In the future, authors should continue to use java.util.logging with an appropriate log level to log messages, so that users have full control over the logging output by OpenTelemetry.

[codecov]

Codecov Report

Merging #1501 into master will not change coverage.
The diff coverage is n/a.

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  Coverage     87.03%   87.03%           
  Complexity     1369     1369           
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  Files           163      163           
  Lines          5205     5205           
  Branches        490      490           
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  Hits           4530     4530           
  Misses          493      493           
  Partials        182      182           

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[anuraaga]

Thanks!

[thisthat]

I don't know how much the API changes from 7 to 8, so this suggestion might not make sense.

Suggested change

	OpenTelemetry uses [java.util.logging](https://docs.oracle.com/javase/8/docs/api/java/util/logging/package-summary.html)
	OpenTelemetry uses [java.util.logging](https://docs.oracle.com/javase/7/docs/api/java/util/logging/package-summary.html)

[carlosalberto]

Most of the logging we do (all?) happens in the SDK level, where we use Java 8+ ;)

[Oberon00]

The SDK also uses Java 7 AFAIK. If not I would be in trouble. 😄

[Oberon00]

See https://github.com/open-telemetry/opentelemetry-java/blob/v0.7.0/build.gradle#L37-L38. We only use Java 8 for (all) unit tests. But users might be able to use the full Java 8 (or 11 or newer) logging API for configuration, even though the SDK uses only the Java 7 subset for producing the logs.

[MitchellDumovic]

From what I can tell the API does not change significantly from 7 to 8 - all the examples here should still be relevant. Though I agree that it makes the most sense to link the most accurate docs here, I will change this.