Pref: default torrent file handler

Before, the app made itself the default torrent file handler automatically, pissing off some of our users. Now, it's not by default, and you can change it in the prefs.

src/renderer/lib/migrations.js

@@ -25,6 +25,10 @@ function run (state) {
     migrate_0_7_2(state.saved)
   }
 
+  if (semver.lt(version, '0.11.0')) {
+    migrate_0_11_0(state.saved)
+  }
+
   // Config is now on the new version
   state.saved.version = config.APP_VERSION
 }
@@ -93,3 +97,10 @@ function migrate_0_7_2 (saved) {
     }
   }
 }
+
+function migrate_0_11_0 (saved) {
+  if (saved.prefs.isFileHandler === undefined) {
+    // The app used to make itself the default torrent file handler automatically
+    saved.prefs.isFileHandler = true
+  }
+}