New feature:

- The metadata of the deleted files will be kept on the database by default.
- We can see the history of deleted files.
- Update information became to be shown on the major upgrade.

Fixed:
- `Pick file to show` was renamed to `Pick a file to show.
- Files in the `Pick a file to show` are now ordered by their modified date descent.

styles.css

@@ -93,6 +93,10 @@
     padding-left: 4px;
 }
 
+.sls-header-button {
+    margin-left: 2em;
+}
+
 .sls-hidden {
     display: none;
 }