Fix a few bugs:

- The downloaded amount shown in the torrent list was incorrect.
- The virtual "Stopped" only appeared errornously on complete torrents.

Also changed the UpdateGraphData method so only the last 50 down/up speeds are stored, I believe storing every single one for a prolonged periode can lead to a high memory usage.
Fix ByteFlood issue #64.

https://github.com/hexafluoride/byteflood/issues/64
Get rid of unnecessary dependency properties.
Make better use of the session status object and remember to dispose it.
Fix MainWindow title.
Merge pull request #65 from diantahoc/master

Bug fixes.