Running `make test-backend` will delete `data/` due to reloading the configuration and resetting the appdatapath.
This PR removes this unnecessary config reload but also adds extra code in to the unittest main to prevent its cleanup from deleting the wrong directory.
Signed-off-by: Andrew Thornton <art27@cantab.net>
* Improve install code to avoid low-level mistakes.
If a user tries to do a re-install in a Gitea database, they gets a warning and double check.
When Gitea runs, it never create empty app.ini automatically.
Also some small (related) refactoring:
* Refactor db.InitEngine related logic make it more clean (especially for the install code)
* Move some i18n strings out from setting.go to make the setting.go can be easily maintained.
* Show errors in CLI code if an incorrect app.ini is used.
* APP_DATA_PATH is created when installing, and checked when starting (no empty directory is created any more).
