Revert to JDK 16

BUILD.md

		Download and install the following software packages:

		-* [JDK 17](https://bell-sw.com/pages/downloads/?version=java-17-lts&package=jdk-full) (Full JDK + JavaFX)
		+* [JDK 16](https://bell-sw.com/pages/downloads/?version=java-16) (Full JDK + JavaFX)
		* [Gradle 7.2](https://gradle.org/releases)
		* [Git 2.33](https://git-scm.com/downloads)

README.md

		On other platforms, start the application as follows:

		-1. Download the full version of the Java Runtime Environment, [JRE 17](https://bell-sw.com/pages/downloads/?version=java-17-lts&package=jre-full#mn).
		+1. Download the full version of the Java Runtime Environment, [JRE 16](https://bell-sw.com/pages/downloads/?version=java-16).
		1. Install the JRE.
		1. Open a terminal window.

build.gradle


		def moduleSecurity = [
		- "--add-modules javafx.swing,javafx.controls,javafx.fxml,javafx.media,javafx.web,javafx.base,javafx.graphics",
		+ "--add-modules=javafx.base,javafx.graphics,javafx.swing,javafx.controls,javafx.media,javafx.fxml",
		"--add-opens=javafx.controls/javafx.scene.control=ALL-UNNAMED",
		"--add-opens=javafx.controls/javafx.scene.control.skin=ALL-UNNAMED",


		dependencies {
		- def v_junit = '5.7.2'
		+ def v_junit = '5.8.1'
		def v_flexmark = '0.62.2'
		def v_jackson = '2.13.0'


		implementation 'org.apache.commons:commons-configuration2:2.7'
		+ //noinspection GradlePackageUpdate
		implementation 'commons-beanutils:commons-beanutils:1.9.4'


		}

		- testImplementation "org.junit.jupiter:junit-jupiter-api:${v_junit}"
		- testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
		+ testImplementation "org.junit.jupiter:junit-jupiter-api:5.8.1"
		+ testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'

		testImplementation "org.testfx:testfx-junit5:4.0.16-alpha"

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