Collection deletion: mark as deleted in cache, but don't actually delete.

This is important for protecting against potential data loss.

app/src/main/java/com/etesync/syncadapter/ui/DeleteCollectionFragment.java

@@ -120,7 +120,9 @@ public class DeleteCollectionFragment extends DialogFragment implements LoaderMa
 
                 JournalManager journalManager = new JournalManager(HttpClient.create(getContext(), account), principal);
                 journalManager.deleteJournal(new JournalManager.Journal(settings.password(), collectionInfo.toJson(), collectionInfo.url));
-                data.delete(JournalEntity.fetch(data, collectionInfo.url));
+                JournalEntity journalEntity = JournalEntity.fetch(data, collectionInfo.url);
+                journalEntity.setDeleted(true);
+                data.update(journalEntity);
 
                 return null;
             } catch (Exceptions.HttpException e) {

app/src/main/java/com/etesync/syncadapter/ui/ViewCollectionActivity.java

@@ -57,7 +57,7 @@ public class ViewCollectionActivity extends AppCompatActivity implements Refresh
         int entryCount = -1;
 
         final JournalEntity journalEntity = JournalEntity.fetch(data, info.url);
-        if (journalEntity == null) {
+        if ((journalEntity == null) || journalEntity.isDeleted()) {
             finish();
             return;
         }