Bump JDK source and target version to 1.8.

Author: heuermh

pom.xml

@@ -57,7 +57,7 @@
     </developer>
   </developers>
   <properties>
-    <jdk.version>1.5</jdk.version>
+    <jdk.version>1.8</jdk.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.build.targetEncoding>UTF-8</project.build.targetEncoding>
     <maxmem>512m</maxmem>