Sets the last time the bookmark for uri was last modified.
If no bookmark for uri is found then it is created.
The "modified" time should only be set when the bookmark's meta-data was actually changed. Every function of BookmarkFile that modifies a bookmark also changes the modification time, except for set_visited.
| this | |
| uri |
a valid URI |
| modified |
a timestamp or -1 to use the current time |