Improved error handling (introduced debugsession commandline argument). Startup/shutdown now more verbose. SSE checks if project was compiled with SSE(2)... not sure if windows would reach it if hardware lacked support, but linux/mac may (from V2). Fixed Mac crashes in deferred.

indra/newview/llurlwhitelist.cpp

@@ -121,6 +121,12 @@ bool LLUrlWhiteList::save ()
 	// build filename for each user
 	std::string resolvedFilename = gDirUtilp->getExpandedFilename ( LL_PATH_PER_SL_ACCOUNT, mFilename );
 
+	if (resolvedFilename.empty())
+	{
+		llinfos << "No per-user dir for saving URL whitelist - presumably not logged in yet.  Skipping." << llendl;
+		return false;
+	}
+
 	// open a file for writing
 	llofstream file ( resolvedFilename );
 	if ( file.is_open () )