Regarding help-echo, glyphs, and the fringe

[JD Smith]

I have noticed that adding a help-echo property to items in the margin
does not result in a tool-tip on mouse-over.  Is this the expected
behavior?  Will this be true of glyphs placed in the fringe as well?
Is fringe glyph programmability slated for a coming release?  Ideally,
I'd like to be able to install a special mouse keymap and provide
help-echo on glyphs in the margin and/or fringe (when that is
available).  Any suggestions?

Thanks,

JD