Add support for noSquash (no-squash) in jms-messaging trigger

It's sometimes required to trigger a job build on every CI message.
To achieve that the XML's noSquash (jjb: no-squash) has to be set to
True.

see triggers section at:
https://wiki.jenkins.io/display/JENKINS/JMS+Messaging+Plugin

Change-Id: I389e59cca4f649379614f7f6247bf76cf4a0ba95

jenkins_jobs/modules/triggers.py

@@ -933,6 +933,12 @@ def jms_messaging(registry, xml_parent, data):
     Requires the Jenkins :jenkins-wiki:`JMS Messaging Plugin
     <JMS+Messaging+Plugin>`.
 
+    :arg bool no-squash: true = schedule a new job for every triggering message.
+        (default false)
+        Normally if a job is queued and another triggering message is received, a new job
+        is not submitted and the job is "squashed" into the job already queued.
+        Setting this option to 'True' forces a new job to be submitted for every triggering
+        message that is received.
     :arg str override-topic: If you need to override the default topic.
         (default '')
     :arg str selector: The JSON or YAML formatted text that conforms to
@@ -968,6 +974,7 @@ def jms_messaging(registry, xml_parent, data):
     mapping = [
         # option, xml name, default value
         ("spec", "spec", ""),
+        ("no-squash", "noSquash", False),
         ("selector", "selector", ""),
         ("provider-name", "providerName", ""),
     ]

tests/triggers/fixtures/jms-messaging001.xml

@@ -3,6 +3,7 @@
   <triggers class="vector">
     <com.redhat.jenkins.plugins.ci.CIBuildTrigger>
       <spec/>
+      <noSquash>true</noSquash>
       <selector>topic = &quot;org.fedoraproject.prod.fedimg.image.upload&quot;</selector>
       <providerName>fedmsg</providerName>
       <checks>

tests/triggers/fixtures/jms-messaging001.yaml

@@ -1,5 +1,6 @@
 triggers:
   - jms-messaging:
+      no-squash: True
       selector: topic = "org.fedoraproject.prod.fedimg.image.upload"
       provider-name: fedmsg
       checks:

tests/triggers/fixtures/jms-messaging002.xml

@@ -3,6 +3,7 @@
   <triggers class="vector">
     <com.redhat.jenkins.plugins.ci.CIBuildTrigger>
       <spec/>
+      <noSquash>false</noSquash>
       <selector>topic = &quot;org.fedoraproject.prod.fedimg.image.upload&quot;</selector>
       <providerName>fedmsg</providerName>
     </com.redhat.jenkins.plugins.ci.CIBuildTrigger>