Include suite name in junit classname attrib for grouping in jenkins

Jenkins groups junit test results by loosely interpreting the
classname attribute of the <testcase> element as a package-qualified
java class name such as java.util.String. It ignores the <testsuite>
elements in the xml. To organize test results we therefore need to
embed the suite name in the classname attribute as if it was a java
package name.

Fixes #922.

include/reporters/catch_reporter_junit.hpp

@@ -150,6 +150,10 @@ namespace Catch {
                 if ( className.empty() )
                     className = "global";
             }
+
+            if ( !m_config->name().empty() )
+                className = m_config->name() + "." + className;
+
             writeSection( className, "", rootSection );
         }