Bring back Java 1.7 source target config changes that got reverted with my branch commits.

git-svn-id: https://hyracks.googlecode.com/svn/branches/fullstack_asterix_stabilization@3038 123451ca-8445-de46-9d55-352943316053
diff --git a/hyracks/hyracks-storage-am-btree/pom.xml b/hyracks/hyracks-storage-am-btree/pom.xml
index a1f362e..f251d51 100644
--- a/hyracks/hyracks-storage-am-btree/pom.xml
+++ b/hyracks/hyracks-storage-am-btree/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>