In qtorrenthandle.cpp exception made caught by reference
In qbtsession.cpp exception made caught by reference
In rssdownloadrule.{cpp,h} 'RssDownloadRule::operator==' made const.
In smtp.cpp fix 'ct' reassign.
Merge pull request #1238 from botanegg/cppcheck

Corrections from running cppcheck.
In statsdialog.cpp fix initialization iEnd
In preferences.h now argument is const references
Merge pull request #1250 from botanegg/cppcheck

Corrections from running cppcheck v2.