Prevent auto refresh when searching or selecting files (in tabletinterface).
Increase size of the rTorrent set_xmlrpc_size_limit to better reflect the real request size whil not having to encode the string twice. Sicne Base64-encoded content is about 1.37 time larger than the original byte strea, a multiplication of 2 is roomy enough (while small files fit in the default max request size anyway, so the Base64 header is no problem).