Archived update site generation

The update site generation is now configured to produce the repository
in zipped format.
It can be found in releng/org.codechecker.eclipse.update/target/ as
codechecker_eclipse_update.zip

Author: vodorok

releng/org.codechecker.eclipse.update/pom.xml

@@ -8,4 +8,17 @@
     <artifactId>org.codechecker.eclipse.update</artifactId>
     <version>1.0.0-SNAPSHOT</version>
     <packaging>eclipse-repository</packaging>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.eclipse.tycho</groupId>
+                <artifactId>tycho-p2-repository-plugin</artifactId>
+                <version>${tycho.version}</version>
+                <configuration>
+                    <finalName>codechecker_eclipse_update</finalName>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>