Fix Qt5 support
Merge pull request #1925 from diger/haiku

Fix Qt5 support
Show stalled downloads that are uploading under the 'Active' filter. Closes #1654."
Forward declare classes where possible in 'TransferListWidget'.
SMTP: send the local hostname as FQDN. See discussion in #1845 for more info.
WINDOWS: Check for python before creating the search engine tab. Prevents the creation of python specific files in the user's PC if no python is found. Closes #1370.
WINDOWS: Don't create keys in the registry if python isn't found. Closes #1370.
WINDOWS: Can now correctly detect 64bit and 32bit python installations on 64bit Windows. Closes #1148 #445 #795 #1708.
WINDOWS: Search first in PATH for python. Closes #956.
Don't display the Search Engine tab by default.
fix import torrent with "Keep incomplete torrents in:" ticked

* also had to account for "Append the label of the torrent to the save path",
  but again, this was only an issue when "Keep incomplete torrents in:" is
  selected

* A multi-file torrent with only one file (ie: a single file within a folder),
  was being treated as a single-file torrent, making it impossible to import.
  Multi-file torrent detection code was copied from libtorrent.  The
  information is available in libtorrent (under torrent_info::m_multifile),
  however it's a private member and I chose to go with copying the code that
  determines it, rather than modifying a library qBittorrent depends on.

Conflicts:
	src/torrentimportdlg.cpp
Sync translations from Transifex and run lupdate.
Fixed extratorrent.cc search engine.
Merge pull request #1919 from masux/master

Fixed extratorrent.cc search engine.