Close button sends client to the tray, statically linked Qt for OSX.
See the Changelog for list of features and fixes currently only available in the nightly builds.
It won't be possible to do this in a way that won't interfere with the way the current client processes searches unfortunately.
Other than the trivial "make two separate searches and merge the results" approach, it might be a good time to add support for new search query messages. Afterall, everyone will be moving to SoulseekQT sooner rather than later...
Seems like this is a basic boolean operator that somehow should be implemented...
couldn't it be implemented by transmitting the operators in a way that's unlikely to be matched by an old client like "(term1||term2) term3 OR term4" => "_Qt_BEG_Qt_ term1 _Qt_OR_Qt_ term2 _Qt_END_Qt_ term3 _Qt_OR_Qt_ term4"