Add missing QTreeWidget::dropEvent to d'n'd atempt occuring in same location.

Remove 'Overwrite attempt' dialog as obsolete. Now moving item, e.g. from folder to same folder, will just make it the last child of the folder.
Drag'n'Drop fixups.

1. Proper event handling
2. Allow folder moving
3. Allow moving into folders
Use new Libtorrent version define.
Merge pull request #705 from sledgehammer999/peer_tab2

Use new Libtorrent version define.
Change seeding algorithm. Increase connections per second.
Simplify code.
Ensure that all columns in the peerlist are showing.
Update AUTHORS file.
Update maintainer info in About dialog.
Improve drawing speed of transferlist with many torrents.
Impove drawing speed of peers list when there are many peers.
Ensure that all tranferlist columns have a size > 0.
Fixed compilation with libtorrent 0.15.x
Update NSIS scripts to use unicode version of installer.
Write BOM in NSIS translations' files.
Made changes for clean up and fix the problem that a new ramdon port is set every time a setting is saved.
more clean up for feature selecting a random port when starts up
new fix for selecting random port when system starts up
Seed rand only at one place.
Port spinbox is now disabled correctly.