Update the lexer generator code to Java 1.7.
diff --git a/asterix-maven-plugins/lexer-generator-maven-plugin/pom.xml b/asterix-maven-plugins/lexer-generator-maven-plugin/pom.xml
index 6b444e8..6be403e 100644
--- a/asterix-maven-plugins/lexer-generator-maven-plugin/pom.xml
+++ b/asterix-maven-plugins/lexer-generator-maven-plugin/pom.xml
@@ -18,8 +18,8 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>2.0.2</version>
         <configuration>
-          <source>1.6</source>
-          <target>1.6</target>
+          <source>1.7</source>
+          <target>1.7</target>
 	  <fork>true</fork>
         </configuration>
       </plugin>