Build with Java 11. Compiler warnings due to deprecated API usage not…

… cleaned up yet

README.md

@@ -25,8 +25,14 @@ all unit tests, and create the jar, run:
 
     ./gradlew build --warning-mode all
 
-RSTA 3.0 and newer requires Java 8 to compile and run.  If you need
-Java 6 compatibility, you'll need to use a 2.6.x version.
+RSTA 4.0 and later requires Java 11 to compile and run. If you need
+to support older Java versions:
+
+| RSTA Version | Required to build (JDK) | Requird to run (JRE) |
+|--------------|-------------------------|----------------------|
+| 4.x          | 11                      | 11                   |
+| 3.x          | 11                      | 8                    |
+| 2.6.x        | 6                       | 6                    |
 
 # Demos
 

gradle.properties

@@ -1,7 +1,9 @@
 # Note that Maven- and signing-related properties are in <maven-home>/gradle.properties
-javaLanguageVersion=8
-osgiRequiredCompatibility=1.8
-version=3.5.3-SNAPSHOT
+
+# This controls the javac "release" version.
+javaLanguageVersion=11
+osgiRequiredCompatibility=11
+version=4.0.0-SNAPSHOT
 
 # Ugh, see https://github.com/gradle/gradle/issues/11308
 systemProp.org.gradle.internal.publish.checksums.insecure=true