Add unscoped info functionality

This adds UNSCOPED_INFO macro, creating a log message that is stored
until the end of next assertion or the end of test case, whichever comes
first. These messages are not scoped locally, unlike messages created by
INFO macro.

include/internal/catch_message.cpp

@@ -47,14 +47,20 @@ namespace Catch {
 
 
     ScopedMessage::ScopedMessage( MessageBuilder const& builder )
-    : m_info( builder.m_info )
+    : m_info( builder.m_info ), m_moved()
     {
         m_info.message = builder.m_stream.str();
         getResultCapture().pushScopedMessage( m_info );
     }
 
+    ScopedMessage::ScopedMessage( ScopedMessage&& old )
+    : m_info( old.m_info ), m_moved()
+    {
+        old.m_moved = true;
+    }
+
     ScopedMessage::~ScopedMessage() {
-        if ( !uncaught_exceptions() ){
+        if ( !uncaught_exceptions() && !m_moved ){
             getResultCapture().popScopedMessage(m_info);
         }
     }