Fix Windows file associations creation.

Now qBittorrent create global ProgId during installation (using HKLM hive)
and allow to associate .torrent files with it (using HKCU).
Fix alertdispatcher.cpp compilability on Qt5.
Fix column resizing issues
Scan Folder dialog now remembers last location

Also fix fs_utils spacing
Merge pull request #1824 from bryanroscoe/rememberLocation

Scan Folder dialog now remembers last location
Fix possible crashes. Closes #1814.
Remove deprecated feature of separate DHT port.
Sync translations from Transifex.
Run lupdate.
Merge pull request #1782 from sorokin/alert-disp-qt5

Fix alertdispatcher.cpp compilability on Qt5.
Merge pull request #1470 from glassez/assoc

Fix Windows file associations creation