- Fixed download from url function (should be a lot less buggy). It improves downloads from search engine since it uses this function

- Removed torrentReactor search engine (hopefully temporarilly) because I can't manage to download from their links using libcurl
- When HTTP response code is 500 (5xx in fact: too busy), downloader will retry 10 times every second.

src/MainWindow.ui

@@ -404,13 +404,6 @@
                </property>
               </widget>
              </item>
-             <item>
-              <widget class="QCheckBox" name="reactor" >
-               <property name="text" >
-                <string/>
-               </property>
-              </widget>
-             </item>
              <item>
               <widget class="QCheckBox" name="isohunt" >
                <property name="text" >