Allow server-side response compression

[FlorianLautenschlager]

Add this to the jetty-gzip.xml in chronix-X.X/chronix-solr-X.X.X/server/etc

<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">

<!-- =============================================================== -->
<!-- Mixin the GZIP Handler                                          -->
<!-- This applies the GZIP Handler to the entire server              -->
<!-- If a GZIP handler is required for an individual context, then   -->
<!-- use a context XML (see test.xml example in distribution)        -->
<!-- =============================================================== -->

<Configure id="Server" class="org.eclipse.jetty.server.Server">
  <Call name="insertHandler">
    <Arg>
      <New id="GzipHandler" class="org.eclipse.jetty.server.handler.gzip.GzipHandler">
    <Set name="minGzipSize"><Property name="jetty.gzip.minGzipSize" deprecated="gzip.minGzipSize" default="0"/></Set>
    <Set name="checkGzExists"><Property name="jetty.gzip.checkGzExists" deprecated="gzip.checkGzExists" default="false"/></Set>
    <Set name="compressionLevel"><Property name="jetty.gzip.compressionLevel" deprecated="gzip.compressionLevel" default="1"/></Set>
    <Set name="excludedAgentPatterns">
      <Array type="String">
        <Item><Property name="jetty.gzip.excludedUserAgent" deprecated="gzip.excludedUserAgent" default=".*MSIE.6\.0.*"/></Item>
      </Array>
    </Set>

    <Set name="includedMethods">
      <Array type="String">
        <Item>GET</Item>
      </Array>
    </Set>

      </New>
    </Arg>
  </Call>
</Configure>

And the following snippet to chronix-X.X/chronix-solr-X.X.X/server/contexts/solr-jetty-context.xml

<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_0.dtd">
<Configure class="org.eclipse.jetty.webapp.WebAppContext">
  <Set name="contextPath"><Property name="hostContext" default="/solr"/></Set>
  <Set name="war"><Property name="jetty.base"/>/solr-webapp/webapp</Set>
  <Set name="defaultsDescriptor"><Property name="jetty.base"/>/etc/webdefault.xml</Set>
  <Set name="extractWAR">false</Set>

  <!-- Enable gzip compression -->
  <Set name="gzipHandler">
    <New class="org.eclipse.jetty.server.handler.gzip.GzipHandler">
      <Set name="minGzipSize">2048</Set>      
    </New>
  </Set>
</Configure>

Add the gzip.mod to chronix-X.X/chronix-solr-X.X.X/server/modules