JunitReporter reimplemented using the new IStreamingReporter interface

* created new AccumulatingReporterBase class for accumulating test
results hierarchically and store them for a single processResults() call
after all tests have been executed; sections are currently not handled,
since their usage are optional and/or could be nested arbitrarily, which
would result in overly complex code, IMHO
* JunitReporter reimplemented on top of this new
AccumulatingReporterBase class
* added support for tracking time spend in each test case, each test
group, and overall tests to the base "*Stats" classes; this enables each
reporter (derived from IStreamingReporter interface) to report the
timings; for now only the JunitReporter takes advantage of that.

include/internal/catch_test_case_info.hpp

@@ -51,16 +51,6 @@ namespace Catch {
         tagsAsString = oss.str();
     }
 
-    TestCaseInfo::TestCaseInfo( TestCaseInfo const& other )
-    :   name( other.name ),
-        className( other.className ),
-        description( other.description ),
-        tags( other.tags ),
-        tagsAsString( other.tagsAsString ),
-        lineInfo( other.lineInfo ),
-        isHidden( other.isHidden )        
-    {}
-
     TestCase::TestCase( ITestCase* testCase, TestCaseInfo const& info ) : TestCaseInfo( info ), test( testCase ) {}
 
     TestCase::TestCase( TestCase const& other )