Adjustments to build the project on JDK 13
diff --git a/.travis.yml b/.travis.yml
index 5a74a84..e181fa9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -48,6 +48,11 @@
       jdk: openjdk11
       env:
         - ARGS=-Dnone
+    - os: linux
+      dist: trusty
+      jdk: openjdk13
+      env:
+        - ARGS=-Dnone
     - os: osx
       osx_image: xcode9.3
       jdk: openjdk11
diff --git a/browser/pom.xml b/browser/pom.xml
index f053eab..d2bb424 100644
--- a/browser/pom.xml
+++ b/browser/pom.xml
@@ -57,21 +57,6 @@
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <configuration>
-                    <skip>false</skip>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>attach-javadocs</id>
-                        <goals>
-                            <goal>jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>2.18.1</version>
             </plugin>
diff --git a/generic/pom.xml b/generic/pom.xml
index b59de10..0008110 100644
--- a/generic/pom.xml
+++ b/generic/pom.xml
@@ -75,8 +75,6 @@
                     <compilerArguments>
                         <Aversion>${project.version}</Aversion>
                     </compilerArguments>
-                    <source>1.6</source>
-                    <target>1.6</target>
                     <testSource>1.8</testSource>
                     <testTarget>1.8</testTarget>
                 </configuration>
@@ -89,21 +87,6 @@
                 </configuration>
             </plugin>
             <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <configuration>
-                    <subpackages>org.netbeans.html.presenters.spi</subpackages>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>attach-javadocs</id>
-                        <goals>
-                            <goal>jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-            <plugin>
                 <groupId>org.netbeans.html</groupId>
                 <artifactId>html4j-maven-plugin</artifactId>
                 <executions>
diff --git a/pom.xml b/pom.xml
index e9c8f4b..da54a00 100644
--- a/pom.xml
+++ b/pom.xml
@@ -33,6 +33,7 @@
   </parent>
   <properties>
       <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+      <javac.source>1.6</javac.source>
       <netbeans.version>RELEASE110</netbeans.version>
       <grizzly.version>2.3.8</grizzly.version>
       <license>COPYING</license>
@@ -278,8 +279,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>2.5.1</version>
                 <configuration>
-                    <source>1.6</source>
-                    <target>1.6</target>
+                    <source>${javac.source}</source>
+                    <target>${javac.source}</target>
                     <testSource>1.8</testSource>
                     <testTarget>1.8</testTarget>
                 </configuration>
@@ -557,5 +558,14 @@
             <jfxrt.jar>${java.home}/lib/jfxrt.jar</jfxrt.jar>
           </properties>
       </profile>
+      <profile>
+          <id>jdk13</id>
+          <activation>
+              <jdk>13</jdk>
+          </activation>
+          <properties>
+              <javac.source>1.7</javac.source>
+          </properties>
+      </profile>
   </profiles>
 </project>
diff --git a/renderer/pom.xml b/renderer/pom.xml
index cb534b8..87f1a0f 100644
--- a/renderer/pom.xml
+++ b/renderer/pom.xml
@@ -47,21 +47,6 @@
                     </instructions>
                 </configuration>
             </plugin>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <configuration>
-                    <skip>false</skip>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>attach-javadocs</id>
-                        <goals>
-                            <goal>jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
         </plugins>
     </build>
     <dependencies>
diff --git a/webkit/pom.xml b/webkit/pom.xml
index 83fcb33..de2c0c1 100644
--- a/webkit/pom.xml
+++ b/webkit/pom.xml
@@ -54,22 +54,6 @@
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <configuration>
-                    <skip>false</skip>
-                    <subpackages>org.netbeans.html.presenters.webkit</subpackages>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>attach-javadocs</id>
-                        <goals>
-                            <goal>jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>2.18.1</version>
                 <configuration>