ISSUE 1180: Enable Shiro variable interpolation

* Allow strings in the 'main' section of the Shiro configuration to be substituted with environment variables

src/server/pom.xml

@@ -238,6 +238,11 @@
             <artifactId>shiro-jaxrs</artifactId>
             <version>${shiro.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-configuration2</artifactId>
+            <version>2.1</version>
+        </dependency>
         <dependency>
             <groupId>io.jsonwebtoken</groupId>
             <artifactId>jjwt</artifactId>