Prepare for 1.3.0 release.

CHANGELOG.md

-# Changes in version 1.3.0 - 2016-0x-xx
+# Changes in version 1.3.0 - 2016-07-06
 
  * Medium changes
    - Parse "package" lines in consensuses and votes.

build.xml

 <project default="jar" name="descriptor" basedir=".">
-  <property name="release.version" value="1.2.0-dev" />
+  <property name="release.version" value="1.3.0" />
   <property name="sources" value="src/main/java"/>
   <property name="resources" value="src/main/resources"/>
   <property name="generated" value="generated/"/>