Fix TorrentReactor search plugin
Fix search engine encoding issues with python3 on Windows

Closes #1996
Replace deprecated sgmllib with HTMLParser/html.parser
Fewer calls to torrent_handle::info_hash()
Use std::vector instead of std::deque in QAlertDispatcher

As we never use {push,pop}_front std::vector works here perfectly.
Also reserve memory for std::vector out of lock.

This could be considered as an optimization, but in reality this is just
using right container in right place. According to my measurements total
speedup is under 0.2%.
Fix race condition in QAlertDispatcher

It was possible that QAlertDispatcher::dispatch() could access (lock)
mutex that was destroyed by main thread. Fix this by moving mutex into a
tag.
Change the program updater's URL for Windows and Mac OS X. Closes #1954.
Merge pull request #2022 from sorokin/for-sledgehammer

a small optimization, a micro optimization and a fix
Merge pull request #1997 from BrunoReX/torrentreactor_fix

Fix TorrentReactor search plugin
Merge pull request #2005 from BrunoReX/python3_utf8

Fix search engine encoding issues with python3 on Windows
Pirate bay search engine update