Merge branch 'stable-5.6'

* stable-5.6:
  Prepare 5.6.1-SNAPSHOT builds
  JGit v5.6.0.201912101111-r

Change-Id: I7824278560d828e1c6e2d540e3372e19507a39c0
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.benchmarks/.classpath

@@ -19,17 +19,6 @@
 	<classpathentry kind="src" path=".apt_generated">
 		<attributes>
 			<attribute name="optional" value="true"/>
-			<attribute name="maven.pomderived" value="true"/>
-			<attribute name="ignore_optional_problems" value="true"/>
-			<attribute name="m2e-apt" value="true"/>
-		</attributes>
-	</classpathentry>
-	<classpathentry kind="src" output="target/test-classes" path="target/generated-test-sources/test-annotations">
-		<attributes>
-			<attribute name="optional" value="true"/>
-			<attribute name="maven.pomderived" value="true"/>
-			<attribute name="ignore_optional_problems" value="true"/>
-			<attribute name="m2e-apt" value="true"/>
 		</attributes>
 	</classpathentry>
 	<classpathentry kind="output" path="target/classes"/>

org.eclipse.jgit.benchmarks/.settings/org.eclipse.jdt.core.prefs

@@ -28,6 +28,7 @@ org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
 org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled
 org.eclipse.jdt.core.compiler.problem.discouragedReference=warning
 org.eclipse.jdt.core.compiler.problem.emptyStatement=warning
+org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=warning
 org.eclipse.jdt.core.compiler.problem.fallthroughCase=warning
@@ -86,6 +87,7 @@ org.eclipse.jdt.core.compiler.problem.redundantSpecificationOfTypeArguments=warn
 org.eclipse.jdt.core.compiler.problem.redundantSuperinterface=error
 org.eclipse.jdt.core.compiler.problem.reportMethodCanBePotentiallyStatic=ignore
 org.eclipse.jdt.core.compiler.problem.reportMethodCanBeStatic=ignore
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
 org.eclipse.jdt.core.compiler.problem.specialParameterHidingField=disabled
 org.eclipse.jdt.core.compiler.problem.staticAccessReceiver=error
 org.eclipse.jdt.core.compiler.problem.suppressOptionalErrors=disabled