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.
RSS Feed was not displaying remote images in html description. Closes #1119
HtmlBrowser didn't handle invalid urls

Urls without scheme weren't working (eg //hostname.com/image.png)
When image couldn't be downloaded app would segfault, now stock warning image is displayed instead.
HtmlBrowser loadResource event loop could cause segfault

If HtmlBrowser was updated multiple times from event loop loadResource()
could cause segfault.
HtmlBrowser will use disk cache for resources
HtmlBrowser disk cache will be saved in fsutils::cacheLocation()