In qtorrenthandle.cpp exception made caught by reference
In qbtsession.cpp exception made caught by reference

Conflicts:
	src/qtlibtorrent/qbtsession.cpp
In rssdownloadrule.{cpp,h} 'RssDownloadRule::operator==' made const.
In smtp.cpp fix 'ct' reassign.
In statsdialog.cpp fix initialization iEnd
In preferences.h now argument is const references
Fix piratebay search engine.
Remove isohunt search engine.
Correctly remove isohunt engine.