Feature request: Add "lock" button

[fugata]

Every so often while trying to copy text from an existing sticky note, or accidentally moving the mouse coursor while typing in a nearby xterm, I would accidentally write over the content of an existing sticky note. It would be extremely helpful to add a "lock" button say on the top of the menu bar of each sticky note. Obviously the lock should be enforced on a note-by-note basis, and not globally.

Many thanks for your consideration!