ac0ab7e211
Fix 265 database locked crash (I'm pretty sure) Previously, all of the various subclasses of FDroidProvider would create their own database open helper in their respective `onCreate()` methods. This seemed to be the cause of the multiple database locked exceptions. Various online articles/SO posts/etc helped come to this conclusion: * http://stackoverflow.com/a/3689883 * http://stackoverflow.com/a/8888606 * https://web.archive.org/web/20150709074733/http://www.dmytrodanylyk.com/pages/blog/concurrent-database.html This should fix #265. In the process, also did away with the two `read()` and `write()` methods that returned a "readable" and "writeable" database respectively. It turns out that it doesn't quite do what I originally thought. There is not much benefit to specifying to the database helper that you want a readable/writeable database. In fact, it is often the case that a call to `read()` would most likely have returned the same instance that is returned by `write()`. The semantics of them were therefore broken, and they've been replaced with `db()`. See merge request !196