meta serialization bug fixes;
convenience meta query builder class MetaQuery to provide better access to json serialization.
diff --git a/pom.xml b/pom.xml
index 3017972..33c05c5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,6 +26,11 @@
     	<artifactId>antlr4-runtime</artifactId>
     	<version>4.0</version>
     </dependency>
+      <dependency>
+          <groupId>com.google.guava</groupId>
+          <artifactId>guava</artifactId>
+          <version>15.0</version>
+      </dependency>
     <dependency>
     	<groupId>com.fasterxml.jackson.core</groupId>
     	<artifactId>jackson-databind</artifactId>