[Companion] Refactor settings system (CompStoreObj/AppData/etc):

~ All stored properties are fully dynamic, using an extended version of the Qt Property System;
 ~ CompStoreObj is now QObject subclass;
 + All properties now have change notifier signals;
 ~ Do not store default values in settings;
 + Add _reset() and _default() functions for each property;
 + Settings import now ignores all non-existent properties automatically;
 + Add settings export functions;
 + Add more version macros;
 ~ Remove template functions;
 ~ Move DownloadBranchType and create NewModelAction enums and register with Qt meta system;
 ~ Multiple efficiency and optimization changes (const functions, literals, etc).

companion/src/fwpreferencesdialog.cpp

@@ -73,7 +73,7 @@ void FirmwarePreferencesDialog::on_sd_dnld_clicked()
   QString fwType = g.profile[g.id()].fwType();
   QStringList list = fwType.split("-");
   QString firmware = QString("%1-%2").arg(list[0]).arg(list[1]);
-  if (g.boundedOpenTxBranch() != BRANCH_NIGHTLY_UNSTABLE) {
+  if (g.boundedOpenTxBranch() != AppData::BRANCH_NIGHTLY_UNSTABLE) {
     url.append(QString("%1/").arg(firmware));
   }
   QDesktopServices::openUrl(url);