Rework session dialog in Qt client to load from .ui


git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14393 f4695dd4-2c0a-0410-b89c-da849a56a58e
Fix license wording in Qt client .cc files to match the rest of the code.


git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14394 f4695dd4-2c0a-0410-b89c-da849a56a58e
#5543: Add a warning panel with id of duplicate torrent (patch by rb07 + personal touch)


git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14395 f4695dd4-2c0a-0410-b89c-da849a56a58e